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• In this paper, we report a 1,8-naphthalimide/ triphenylamine-based fluorescent probe (TPA-NI-NO 2) for the specific detection of 4‑methoxy-thiophenol (MTP) with good selectivity among the thiophenols. • The probe can "turn on" detect MTP with the limit of detection (LOD) of 80 nM and no obvious response to relevant analytes and homologues. • The sensing mechanism was explored by HPLC experiment and the PET process was determined by density functional theory (DFT) calculations. • The Gibbs free energy (DG) analysis for the reaction between the probe and different thiophenols were obtained by the theoretical calculations to study the specificity of the probe. • The probe was successfully applied to monitor the MTP in Hela cells. Thiophenols as a series of industrial products are widely used and high toxicity to the organisms and the environment. The fluorescent probe technique offers important insights into thiophenols convenient sensing. Herein, we report a 1,8-naphthalimide/ triphenylamine-based fluorescent probe (TPA-NI-NO 2) for the specific detection of 4‑methoxy-thiophenol (MTP). The probe can "turn on" specific detect MTP with the limit of detection (LOD) of 80 nM among various relevant analytes and homologues (p -Cl-C 6 H 4 SH, p -NO 2 - C 6 H 4 SH, C 6 H 5 SH and o -CH 3 - C 6 H 5 SH). The sensing mechanism was explored by the HPLC experiment and the PET process was determined by density functional theory (DFT) calculations. In addition, the specificity of the probe was also studied by the Gibbs free energy (ΔG) analysis of the reaction between the probe and different thiophenols. The reaction between probe and MTP gives the minimum of the ΔG value (∼ -9.7280 kcal/mol) and that of other thiophenols-mediated is -2.5283 to -5.8911 kcal/mol, which proves the thermodynamic chemical equilibrium can optimize the design of reaction-based fluorescent probes with excellent specificity. At last, TPA-NI-NO 2 was successfully applied to Hela cells imaging. [Display omitted] [ABSTRACT FROM AUTHOR]

• Promising G-quadruplex binders: chroman derivatives ligands & their BF2-complexes. • These compounds stabilize parallel and mixed hybrid G-quadruplex structures. • In vitro and cellular studies: biophysical analyses demonstrate binding affinity in both contexts. • Molecular docking: computational study supports binding of chroman complexes to G-quadruplex. • Potential fluorescent ligands: these compounds offer new options for G-quadruplex targeting ligands. Currently, G-quadruplex structure targeting strategies are considered as a promising anticancer approach. The purpose of this research is to expand the options for G-quadruplex targeting ligands, particularly emphasizing fluorescent ligands. Our study contributes to the field by providing additional choices for G-quadruplex binders with a notable focus on selectivity towards G-quadruplex topology over duplex DNA. In the search of selective and potent G-quadruplex binders, here we discuss an analysis of a few chroman derivatives ligands named A and C and their respective borondifluoride complexes B and D as a quadruplex targeting compounds which found to stabilize G-quadruplex structure. To investigate the binding characteristics of these molecules with G-quadruplex vs. duplex selectivity, In vitro biophysical studies were performed by steady-state fluorescence, UV–visible titration, fluorescent TO displacement assay, CD thermal melting, circular dichroism spectroscopy, and cellular imaging by employing both telomeric and PRCC G-quadruplex forming sequences. Our investigation shows that these chromam ligands and their complexes are able to selectively bind and stabilize parallel and mixed hybrid topology of G-quadruplex both In vitro and in cellular conditions. A molecular docking and MD simulation study also suggests the binding of these compounds with G-quadruplex conformation. Collectively our study suggests these chroman complexes for the first time as a potentially useful fluorescent chemical product for G-quadruplex specific ligands and expands an option for G-quadruplex targeting ligands. [Display omitted] [ABSTRACT FROM AUTHOR]

• Constructing a complex (1) with precise structures by introducing luminescent groups triphenylphosphine (TPA), is used for treatment and imaging. • Within 0.5 h, 1 can be distributed into cells, performing effective cell imaging. • 1 can be used for CDT, promoting oxidative stress and causing cell apoptosis. The combination of imaging and treatment is the fundamental strategy for achieving precise anticancer treatment. This article constructs a copper(I) complex (1) by aminourea derivative containing triphenylamine (TPA). 1 with precise structure, can be used for cell imaging and chemodynamic therapy (CDT). Within 0.5 h, 1 can be distributed into the mitochondria of T24 cells, performing effective cell imaging and then promoting oxidative stress and causing cell apoptosis. A precise complex with luminescent triphenylphosphine (TPA) group, is used for the effective cell imaging, promoting oxidative stress and causing cell apoptosis. [Display omitted] [ABSTRACT FROM AUTHOR]

• Novel indium(III) phthalocyanines baring mercaptopyridine groups and their quaternized derivatives were synthesized. • Singlet oxygen generation and photostability of these phthalocyanines were investigated. • Electrochemical biosensing assay conducted with disposable pencil graphite electrodes. • Interaction of phthalocyanines with AS1411 examined by electrochemical impedance spectroscopy as well as spectroscopic techniques. • The developed targeted PDT agent has the potential for breast cancer treatment in the future. In the study, the novel indium(III) phthalocyanines containing 4-mercaptopyridine groups as substituents on the peripheral (Pc3) or non-peripheral (Pc8) tetra-and peripheral octa (Pc13) positions were synthesized. After then, the synthesized phthalocyanines were converted to their water-soluble derivatives that are Pc5, Pc10, and Pc15 by the quaternization of the nitrogen atoms on the substituents. These new phthalocyanines have been characterized by various spectroscopic methods such as FT-IR, 1H NMR, elemental analysis, UV–vis, MALDI-TOF mass spectra. Photochemical properties were also investigated for the synthesized phthalocyanines. In this study; quaternized derivatives were studied in DMSO and aqueous solutions, while non-quaternized derivatives were studied only in DMSO. The interaction between AS1411 and three phthalocyanines (Pc5, Pc10 , and Pc15) was investigated using spectroscopic methods and electrochemical impedance spectroscopy technique combined with pencil graphite electrodes (PGEs). The cytotoxic activity of AS1411 and each phthalocyanine was investigated in the MCF-7 and doxorubicin (Dox) resistant MCF-7/DOX-R cell lines in the presence and absence of Dox. The photodynamic therapy (PDT) activity of Pc5, Pc10 , and Pc15 and their AS1411 conjugates was investigated on MCF-7, MCF-7/DOX-R and MCF-10A cells. The IC 50 values for MCF-7 cells were found as 1.1, 0.46, and 0.46 mM for Pc5 and 0.58, 0.34, and 0.32 mM for Pc5 -AS1411 conjugate in the absence of irradiation and radiation with 7 J and 20 J. The values for MCF-7/DOX-R cells were found 0.81, 0.30, and 0.11 mM for Pc5 and 0.39, 0.12, and 0.15 mM for Pc5 -AS1411 conjugate without irradiation and radiation with 7 J and 20 J, respectively. Apoptosis and cell imaging studies showed that conjugation of the phthalocyanines with AS1411 induced apoptosis in both cell lines and increases the intracellular entry of phthalocyanine Pc5. [ABSTRACT FROM AUTHOR]

• Two thiazole-fused fluoran-based fluorescent probes for copper ions have been prepared. • The two probes show high selectivity and sensitivity for copper ions. • MTFH achieves red emission (632 nm) towards copper ions due to the methyl functionalization. • The two probes can be utilized for tracing intracellular copper ions. In this work, two thiazole-fused fluoran-based fluorescent probes 8′-(diethylamino)-2-((2-hydroxyethyl) amino)spiro[isoindoline-1,11′-xantheno[2, 1- d ]thiazol]-3-one (TFH) and (8′-(diethylamino)-2-((2-hydroxyethyl)amino)-3′-methyl-3-oxospiro[isoindoline-1,11′-xantheno[2,1- d ]thiazol]-3′-ium).BF 4 (MTFH) have been prepared for copper ions. It should be noted that MTFH achieves red emission (632 nm) compared with TFH in the presence of copper ion, which mainly can be attributed to the methylation of molecule MTFH that induced more stronger ICT effect. The two probes show selective fluorescence off-on signal changes towards copper ions with detection limits of 8.8 and 60.8 nM. Copper ion detection can be conducted in a wide pH range including the physiological pH environment. Both TFH and MTFH exhibit suitable cytotoxicity and have been used for copper ion tracing in living cells. However, no other significant improvements of MTFH in sensing performance can be observed when compared with TFH. Two thiazole-fused fluoran-based fluorescent probes have been prepared for selectively and sensitively sensing copper ions, in particular, the methyl functionalization probe achieves red emission mainly due to a stronger ICT effect. [Display omitted] [ABSTRACT FROM AUTHOR]

• The probe XCCC is a near infrared probe(λ em = 696 nm) with a large Stokes shift value (196 nm). • The probe XCCC is sensitive (LOD = 11.4 nM) and fast for HSO 3 − (within 30 s). • The probe XCCC has been successfully applied to detect HSO 3 − in natural environment and biological system. A colorimetric near-infrared fluorescent probe was designed and synthesized in this paper. The probe XCCC was obtained by simple condensation of 6-(diethylamino)-2,3-dihydro-1 H -xanthene-4-carbaldehyde and 3-cyanoacetyl indoles. XCCC detects HSO 3 − through 1, 4-nucleophilic addition reaction, with obvious near-infrared fluorescence quenching (λ em = 696 nm), and the solution color changes from pink to pale yellow under natural light to realize naked eye recognition. In addition, XCCC has a super large Stokes shift value (196 nm) by calculation. The sensitivity of XCCC and HSO 3 − in the concentration range of 0 ∼ 60 μM is excellent, and the LOD value is as low as 11.4 nM. It is very fast for XCCC to detect HSO 3 − in real time (30 s), and the reversible cycle of HSO 3 −- H 2 O 2 is realized (5 times). In practical application, XCCC successfully detected HSO 3 − qualitatively and quantitatively in actual water samples. Furthermore, we made XCCC into fluorescent test strips to qualitatively detect HSO 3 − in red wine. In particular, XCCC was used to realize exogenous cell imaging of HSO 3 − with different concentrations and reversible cell imaging of HSO 3 −-H 2 O 2 in A549 cells. It shows that probe XCCC has a potential application prospect in food samples and life systems. [Display omitted] [ABSTRACT FROM AUTHOR]

• The probe exhibited high selectivity and good sensitivity towards Al3+ and Fe3+ metal ions. • The detection limits were 0.76 nM and 0.49 nM respectively. • Biological experiments have shown that the RP probe has good membrane permeability and has the potential to detect Al3+ and Fe3+ in living cells. Fluorescent probe molecules have the advantages of good selectivity, high sensitivity, and easy operation, which have attracted much attention. In this paper, a novel symmetric rhodamine fluorescent probe with structural rigidity was synthesized by a simple reaction using rhodamine 6G as raw material. And it was characterized by NMR and electrospray spray mass spectrometry. Single crystal was prepared by solvent evaporation method, which was the first single crystal of the compound reported domestically and internationally. Special spiral ring structures were observed inside the crystal. Among different competing cations, the probe exhibited high selectivity and good sensitivity towards Al3+ and Fe3+ metal ions. The limits of detection were 0.76 nM and 0.49 nM, respectively. In the presence of Al3+ and Fe3+, the solution changed from colorless to pink. At the same time, there was a significant shift in the UV– vis spectrum and fluorescence emission spectrum. The UV– vis absorption peak appeared at 530 nm, while the emission at 556 nm was turned on. In addition, biological experiments have shown that the RP probe has good membrane permeability and has the potential to detect Al3+ and Fe3+ in Hela cells. [Display omitted] [ABSTRACT FROM AUTHOR]

• Two site II-targeting probes were designed with full consideration of their binding to HSA. • TAB2/6 displayed favorable selective HSA sensitivity and strong HSA binding ability. • WP5-TAB2/6 complex inherited the responsiveness and binding ability of the probe. • WP5-TAB2/6 complex self-assembled into a vesicular supramolecular fluorescent probe. • The supramolecular probe could be used for HSA-mediated cell imaging and drug delivery. Two cationic probes (named TAB2 and TAB6) specifically for binding to site II in human serum albumin (HSA) were designed and synthesized. Both probes exhibited selective fluorescence "turn-on" responsiveness to site II in HSA, though minor differences in their cationic terminals resulted in notable variations in their albumin responsiveness. TAB2 and TAB6 also exhibited strong binding affinity toward HSA. The presence of phenylbutazone, ibuprofen, and lidocaine had minimal impact on the albumin responsiveness of these probes. Furthermore, the complex formed by TAB2/6 and water-soluble pillar[5]arene (WP5) showed enhanced HSA site II-targeting fluorescence responsiveness. More importantly, the WP5-TAB2/6 complex self-assembled into vesicular supramolecular probes in aqueous solution (pH=7.4). Those supramolecular probes were promising for HSA-mediated cell imaging and act as a pH-sensitive drug-delivery platform to enhance the anticancer efficiency of doxorubicin (DOX). [Display omitted] [ABSTRACT FROM AUTHOR]

• A ratiometric probe for the quantitative detection of L-Cys was prepared. • Detecting L-Cys with high sensitivity (0.32 μM) and fast response time (90 s). • Smartphone fluorescence imaging and fluorescent test strips. Cysteine is an important thiol involved in the vital activities of the human body, and many physiological processes in the body are associated with it. Accurate detection of cysteine is of great importance in monitoring the development of diseases. In this paper, we prepared a ratiometric flavonoid fluorescent probe, HDFA, that exhibits specific selectivity for L-cysteine. HDFA was the first fluorescent probe that can distinguish between L-cysteine and D-cysteine. When detecting L-cysteine, the fluorescence color changed from blue to yellow, and the fluorescence quantum yield increased from 16.96 % to 21.30 %. The probe has a short response time (90 s) to L-cysteine, a large Stokes shift (186 nm), good selectivity, and anti-interference, and the detection limit was 0.32 μM. The detection mechanism was confirmed by mass spectrometry. In addition, HDFA has good applications in cell imaging, smartphone fluorescence imaging and fluorescence test strip detection. [Display omitted] [ABSTRACT FROM AUTHOR]

• The two novel fluorescent probes Z 1 and Z 2 based have been designed and synthesized base on pyrazole derivative to recognize hydrazine • The probe Z 1-2 have ICT characteristics with large Stokes shifts. • The probe Z 1-2 could be made into test paper strips for detection of hydrazine. • The probe Z 1-2 can be used in detection of N 2 H 4 in environmental soil samples and cell imaging. Here, the two novel fluorescent probes Z 1 and Z 2 have been designed and synthesized based on pyrazole derivative to recognize hydrazine, and the molecular structure was determined by 1H NMR, 13C NMR, and ESI-MS. The obtained probe molecules have AIE and ICT characteristics. Nuclear magnetic resonance analysis (NMR) and theoretical calculations were used to confirm the identification mechanism. Probes Z 1 and Z 2 have good selectivity, low detection limits (0.197 µM and 0.185 µM, respectively), and high sensitivity. Probes Z 1 and Z 2 have large Stokes shifts of 198 nm and 211 nm, respectively. The probes also could be made into test paper strips for the detection of hydrazine. Furthermore, the probes can be used in the detection of N 2 H 4 in environmental soil samples and cell imaging. The results showed that the synthetic probe had good biocompatibility. Cell imaging experiments were performed to apply probes to the detection of hydrazine hydrate in HeLa cells. [Display omitted] [ABSTRACT FROM AUTHOR]

• Photoluminescent PS-CDs were prepared using pumpkin seeds as a novel carbon source. • The proposed method is simple, economic and environmental friendly. • A strong blue emission with high quantum yield of 12.7 % was obtained by PS-CDs. • PS-CDs are used as potential chemosensor for Cu2+ and Fe3+ ions in aqueous media. • PS-CDs are low toxic and its metal complexes used as cell imaging with HCT-116 cells. A facile and efficient green synthesis of photoluminescent carbon dots (CDs) was achieved using pumpkin seeds (PS) through the hydrothermal-carbonization method. Pumpkin seeds , well-known for their nutrient-rich composition, offer potential health benefits, including heightened fertility, enhanced heart health, and improved blood sugar regulation. The as-synthesized PS-CDs characterization through UV–vis, photoluminescence (PL), FTIR, XRD, and HR(TEM) analysis. The PL PS-CDs exhibited an excitation-dependent behavior, with the peak shifting from 410 nm to 475 nm under excitation wavelengths ranging from 270 nm to 400 nm. Notably, the synthesized PS-CDs displayed outstanding advantages, such as a high fluorescent quantum yield of 12.7 % with bright blue emissions when exposed to UV light at 365 nm. High-resolution TEM images revealed an average size of approximately 4.0 ± 0.2 nm for the synthesized PS-CDs, ranging from 2 to 7 nm with interlayer distance of 0.21 nm. PL spectra of PS-CDs solution, with an excitation wavelength of 338 nm and emission wavelength of 420 nm, were examined in the presence of various metal ions (50 μM). The fluorescence lifetime of the PS-CDs showed an exponential curve, with an average lifetime (τ av) of 8.47 ns for Cu2+and 3.61 ns for Fe3+ ions, respectively, which is strongly indicates that quenching occurs through a static mechanism. The PS-CDs exhibited high sensitivity and selectivity towards Cu2+ and Fe3+ ions, with a linear relationship observed up to a concentration of 50 μM and detection limits of 0.43 and 0.11 μM (S/ N = 3), respectively. Moreover, the low-toxicity and strongly fluorescent PS-CDs were successfully applied for cell imaging. The practical utility of the developed sensor was determined through the analysis of Cu2+ and Fe3+ ions in spiked water samples, highlighting its considerable analytical and bioanalytical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel fluorescent probe DYH was fabricated and characterized. • In CH 3 CN/HEPES (7/3, v/v, HEPES 100 mM pH = 7.3), the probe DYH can continuously detect Cu2+ and S2−. • DYH has a wide linear range and low detection limit for Cu2+ (0.56 μM) and S2− (0.67 μM). • DYH was found useful for imaging of Cu2+ and S2− in living cells. In this paper, a fluorescent probe methyl(E)-2-(3-(benzo[ d ]thiazol-2-yl)-2‑hydroxy -5-methylbenzylidene) hydrazine-1-carboxylate (DYH) based on benzothiazole was designed and synthesized. The characterization involved NMR, HRMS, and crystal structure analysis. In case of the existence of other competing cations, the probe DYH showed high-affinity for Cu2+, and the resultant DYH Cu2+ showed exceptional capacity to recognize S2− in CH 3 CN/HEPES (7/3, v/v, HEPES 0.1 M, pH = 7.3). The detection limits of DYH for Cu2+ and DYH Cu2+ for S2− were 0.56 μM and 0.67 μM, respectively. It was determined that the binding stoichiometry between the DYH and Cu2+, as well as DYH Cu2+ and S2−, was 1:1 according to the job's curve. The pH of the probe and complex was stable between 4 and 10. Colorimetric experiments of the probe DYH were conducted using test paper as a carrier. Additionally, DYH was used for fluorescence imaging of Cu2+ and S2− in Hela cells with poor cellular toxicity and good cell permeability. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new triphenylamine-furan hydrazone-based fluorescent sensor (TPA-TF) for Cu2+ was developed. • TPA-TF showed excellent water solubility, rapid response, long linear detection range, and wide pH range in applications. • TPA-TF was applied to image Cu2+ in HeLa and U251 cells. A novel fluorescent probe (TPA-TF) was designed and synthesized, incorporating triphenylamine-thiophene moieties coupled with furan and a hydrazone. First, the TPA-TF can be used as a sensor to detect Cu2+ in the environment/biosystem through an effective fluorescence quenching due to chelation-enhanced fluorescence quenching (CHEQ) and inhibiting the photoinduced electron transfer (PET) process. Various fluorescence spectra and density functional theory (DFT) computations were used to clarify the TPA-TF to Cu2+ detection characteristics. The Cu2+ sensor TPA-TF exhibited a fast response time of one minute. In this study, the linear range concentration for the Cu2+ ion detection was 0–1000 μM, with a broad pH working range (pH 2.7–7.4), and the detection limit of the sensor was 6.08 μM. With its broad applicability, the TPA-TF sensor was successfully used to detect and photograph Cu2+ in live cells, demonstrating its considerable potential for applications in biological imaging. [Display omitted] [ABSTRACT FROM AUTHOR]

• A tetraphenyl ethylene-fused rhodamine dye TPE-RhMe has been facilely synthesized. • TPE-RhMe exhibits large Stoke shifts and red emission. • TPE-RhMe can be used as a viscosity tracer in invitro and in vivo. • TPE-RhMe exhibits excellent performance in mitochondria targeting. Long-wavelength (>600 nm) luminescent organic dyes with organelle targeting function attract much attention because they can effectively avoid interference from the biological background fluorescence, etc. In this manuscript, tetraphenyl ethylene (TPE)-fused rhodamine dye, namely TPE-RhMe, has been facilely constructed with large Stokes shifts (58–199 nm) and red emission (601–718 nm) by the introduction of a multi-rotor-functionalized TPE moiety. The multi-rotor-contained structure of TPE-RhMe makes it a viscosity probe, which shows an emission enhancement in glycerol/water mixture with the increase of glycerol. Meanwhile, TPE-RhMe shows high selectivity towards glycerol among various analytes and the sensing measurement can be conducted over a board pH range (1.0–8.0). In addition, TPE-RhMe can also monitor viscosity enhancement through fluorescence lifetime changes. Significantly, TPE-RhMe exhibits a distinct fluorescence enhancement in 4T1 and HeLa cells compared with LO2 cells and presents a promising application in distinguishing normal and tumor cells. Furthermore, TPE-RhMe can be utilized for tracing the stimulated viscosity enhancement by using HeLa cells. Importantly, TPE-RhMe displays excellent performance in mitochondria targeting with a Pearson's correlation coefficient (PCC) value of 0.96. A tetraphenyl ethylene-fused rhodamine dye with large Stokes shift and red emission has been constructed for viscosity sensing and mitochondria-targeted cell imaging. [Display omitted] [ABSTRACT FROM AUTHOR]

• A series of nucleolus-targeted benzazole- N,N -dialkylphenylamines (BX1-14) were synthesized based on Thioflavin T. • Among the compounds, BX-6 and BX-13 were found to have large stokes shifts and high quantum yields. • BX-6 and BX-13 compounds selectively targeted the nucleolus in DLD-1 and HT-29 cancer cell lines. • The molecular docking results indicated that the compounds could target the RNA-rich region in the nucleolus. • The compounds have potential as a biomarker in cell imaging of nucleolus-associated changes. Considered the brain of the nucleus, alterations in the structure and function of the nucleolus are linked to numerous cellular functions and, consequently, contribute to several diseases. The identification of nucleolar morphology and activity via novel biomarkers presents new avenues for the development of therapeutic approaches for a variety of human diseases, including cancer, neurodegeneration, and aging. Therefore, specific detection of the nucleolus with fluorescence probes is of critical importance for clinical applications. In the present study, a series of benzoxazole- N,N -dialkylphenylamines derivative compounds were designed and synthesized based on the benzothiazole-based fluorescence probe Thioflavin T (ThT). Among the compounds, BX-3 and BX-16, which carry electron-withdrawing substituents in the benzoxazole ring, were observed to have higher fluorescence emission at wavelengths of 470 and 465 nM, respectively. The general morphology and divisions of the cells were examined under inverted and light microscopes, respectively, and the fluorescence potentials of selected compounds were determined using immunofluorescence microscopy. The fluorescence intensity of molecules and 3D interactive surface plot images of cells were analyzed using ImageJ software. Cell imaging analyses showed that BX-6 and BX-13, like ThT, specifically stain the cell nucleolus. Moreover, molecular docking studies showed that the compounds could identify the RNA-rich nucleolus by binding with high affinity to the guanine region in the RNA structure. The results suggest that the compounds may be an initial route in developing specific biosensor compounds for nucleolus imaging. [Display omitted] [ABSTRACT FROM AUTHOR]

• An AIE active anthracene-based Schiff base probe ' AP' is firstly reported as Cu2+ sensor. • AP has negligible interfering effect on Cu2+ detection with nanomolar LOD. • AP - AP * in AIE and AP − Cu2+ − AP * excimer formation is established from UV/PL, DFT and 1H NMR titration debriefings. • Crystalline and nanostructural features of AIE and sensors are authorized by PXRD, SEM, TEM and DLS studies. • Proposed method is validated by cellular imaging and real water recovery interrogations. An aggregation induced emission (AIE) active anthracene-based Schiff base probe "(2-((anthracen-9-ylmethylene) amino) phenol); AP " was synthesized via one-pot reaction and utilized in "turn-on" detection of Cu2+ ions. Ultraviolet–visible and photoluminescence (UV–vis/PL) interrogations confirm the AIE between 0 and 99 % water fraction (f w) and high selectivity of AP to Cu2+. PL studies establish the linear regression of Cu2+ between 0 and 24 µM with a detection limit (LOD) of 53.2 nM. The Job plot and high-resolution mass (HR-mass) data affirm 2:1 stoichiometry and the association constant (K a) value appraised as 1.88 × 10−4 M−2. Time-resolved photoluminescence (TRPL) studies reveal decay kinetics of AIE, Cu2+ sensors and complex's reversibility. Moreover, 1H NMR titration and density functional theory (DFT) investigations identify the binding mode, π-π stacking in AIE, AP − Cu2+ − AP * excimer formation, band gap variations and involvement of photoinduced electron transfer (PET) and chelation enhanced fluorescence (CHEF) mechanism. Crystallinity and nanostructural variations of AIE and Cu2+ sensors are investigated by using powder-X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and dynamic light scattering (DLS). AIE and Cu2+ sensory method are validated by MDA-MB-231 cellular imaging studies. Finally, real water-based titrations show nanomolar LODs and recoveries > 97 % with RSDs < 3.5 %. [ABSTRACT FROM AUTHOR]

• Black carrots are an excellent source of carbon dot production. • Biomass-derived CDs demonstrate high anti-metastatic potential;. • CDs are useful for image-guided anti-cancer therapy;. • We explain the basis for the excitation-independent emission wavelength of CDs at 612 nm. This paper explains the basis for the excitation energy-independent fluorescence emission of biomass-derived carbon dots (CDs) and shows that these CDs have excellent anti-melanoma and anti-metastatic potential. Additionally, we demonstrate that the black carrots´-derived CDs can be exploited as cell cycle-sensing agents, because of the interaction with chromatin material. Besides their optical properties, fluorescent CDs have gained increased attention for image-guided cancer treatment due to their water solubility, environmental friendliness, affordability, ease of synthesis, and primary biocompatibility. CDs have excellent photostability, determined by their precursors and synthesis pathways. In this study, CDs with chemically homogenous surface functional groups were made using a hydrothermal technique from black carrot extract, an anthocyanin-rich substance derived from biomass. The anti-cancer and anti-metastatic properties of black carrot-derived CDs can be attributed to flavylium cations on the surface, spherical forms, and high water dispersibility. Most importantly, these CDs demonstrate a stable emission at a single wavelength, 612 nm, independent of the excitation energy, which we have explained theoretically for the first time. [Display omitted] [ABSTRACT FROM AUTHOR]

• A series of rhodamine pyrimidine derivatives (RP1,RP2,RP3 and RP4) and rhodamine pyrimidine nido-carborane derivatives (RPB1,RPB2,RPB3 and RPB4) were successfully synthesized. • Compounds RP4 and RPB4 have a good inhibitory effect on tumor cells in cytotoxicity experiments. • According to cell imaging experiments, compounds RP4 and RPB4 can enter tumor cells through the cell membrane and have good cell compatibility. Because of the advantages of fluorescent drugs consisting of fluorescent dyes and compounds with anticancer activity for therapeutic diagnostics and personalized medicine. A series of fluorescent antitumor drugs rhodamine pyrimidine derivatives (RP1, RP2, RP3 and RP4) were synthesized by linking rhodamine B and pyrimidine derivatives through ethylenediamine bridge and then introduced into nido- carborane to form fluorescent salt derivatives (RPB1, RPB2, RPB3, and RPB4). It improves the tumor targeting and imaging ability of pyrimidine derivatives. By CCK8, it was found that the inhibition rates of RP4 and RPB4 at 10 μg/mL on HeLa, PC-3 and L02 cells were 70.4 %, 68.7 %, 86.1 % and 72.5 %, 76.4 %, 81.0 %, respectively. The compound has strong inhibitory effect on cancer cells. The logP values of compounds RP4 and RPB4 were between 0 and 3, which were easily absorbed and transported through the cell membrane. Further cell imaging experiments showed that RP4 could enter tumor cells through cell membrane and had good biocompatibility. The experimental results show that compounds RP4 has good imaging capability and tumor targeting, and is a potential fluorescent anticancer agents. [Display omitted] [ABSTRACT FROM AUTHOR]

• A VN62 fluorescent sensor with ESIPT propertywas designed, synthesized and characterized. • VN62 sensor exhibited rapid and stable detection of Al3+ with a remarkable fluorescence enhancement in aqueous solution. • The sensing mechanism of VN62 sensorto Al3+ wasreasonably speculated based on experimental results and theoretical calculations. • VN62 sensor was capable of recognizing Al3+ by test strips and imaging Al3+in plants and living cells. A new acylhydrazone fluorescent sensor (VN62) with excited intramolecular proton transfer (ESIPT) characteristics has been designed and synthesized through condensation of o -vanillin with 6‑hydroxy-2-naphthoic hydrazide for selective detection of Al3+ in aqueous medium. The structure of the VN62 sensor was characterized by various techniques such as 1H and 13C NMR and mass spectrometry, and also confirmed by single crystal X-ray diffraction. The VN62 sensor showed a remarkable fluorescence enhancement response to Al3+ over a broad pH range in a nearly 100 % aqueous solution without interference by most of tested metal ions and anions. Through fluorescence titration and a Job's plot experiment, the binding stoichiometry of VN62 with Al3+ was found to be 1:1. The limit of detection of VN62 toward Al3+ was determined as 39.6 nM and the binding constant was 2.66 × 104 M−1. Comprehensive analyses by HR-MS, 1H NMR and density functional theory calculations illustrated that the VN62 sensor coordinated with Al3+, forming a stable trigonal bipyramid structure complex, which blocked the ESIPT and photoinduced electron transfer processes and simultaneously promoted an intramolecular charge transfer process, thereby leading to strong cyan fluorescence. Moreover, VN62 -loaded test strips were successfully applied for rapid and visual detection of Al3+. Furthermore, the VN62 sensor was used to visualize Al3+in plants and live cells. The results indicated that the VN62 sensor has great potential for detecting Al3+in biological systems. [Display omitted] [ABSTRACT FROM AUTHOR]

• New Yb3+ complex from bulky β-diketone and N based Lewis base was synthesized. • The structure of the complex was found to be octa-coordinate. • The shape analysis shows that the complex has square antiprism (D 4 d) geometry. • The synthesized complex shows good thermal stability. • Efficient NIR luminescence with longer lifetime are observed. We have designed an ytterbium-based complex with perfluorinated beta-diketone and bidentate nitrogen-based heterocyclic base 2-(1H-Imidazol-2-yl) pyridine, [Yb(fod) 3 (impy)]. The octa-coordinate structure of [Yb(fod) 3 (impy)] was confirmed by means of various spectroscopic techniques and theoretical calculations. The photophysical behavior of [Yb(fod) 3 (impy)] demonstrated characteristic emission in NIR region centered at 978 nm with shoulders at 1006 nm and around 1032 nm. Interestingly, the lifetime obtained for the said complex is amounted to 15 µs and good intrinsic quantum yield 0.75 %. The significant spectroscopic measurements suggest that beta-diketone and ancillary ligand employed in the present work are functioning as an efficient sensitizer for ytterbium ion. The synthesized complex [Yb(fod) 3 (impy)] could find significant place in designing of NIR OLEDs, lasers, optical-electronic devices, cell imaging purpose owing to the biocompatible feature of Yb (III) complexes as their emission windows are transparent to body fluids. [Display omitted] [ABSTRACT FROM AUTHOR]

• A HSA sensitive probe MBD was designed by modifying an existing fluorescent agent MPM. • MBD inherited the HSA binding ability of MPM but newly obtained HSA responsiveness. • The aforementioned properties were maintained after MBD formed a complex with WP5. • WP5-MBD complex self-assembled into fluorescent nanoparticles in solution. • The nanoparticles possessed good cell imaging and traceable drug delivery properties. Protein-ligand interaction serves as a critical foundation for intramolecular charge transfer (ICT) probes to bind and recognize proteins. Many fluorescent agents are reported to have favorable protein binding abilities but lack protein sensitivity. Herein, a new serum albumin sensitive ICT probe (named MBD) was synthesized by modifying an existing fluorescent agent MPM. MBD not only inherited the favorable human serum albumin (HSA) binding ability of MPM but also newly obtained favorable serum albumin responsiveness. These properties were maintained after MBD formed a complex with water-soluble pillar[5]arene (WP5). Typical commercial drugs, fluorescent amino acids, fatty acids, and metal ions had negligible effects on the HSA responsiveness of the complex. The WP5-MBD complex possessed strong anti-interference ability in binding and recognizing HSA. Moreover, the WP5-MBD complex self-assembled into supramolecular fluorescent nanoparticles in solution. Such nanoparticles possessed good cell imaging and traceable drug delivery properties, which hold great potential for cancer treatment and diagnosis. [Display omitted] [ABSTRACT FROM AUTHOR]

• 5-Methyl-2-phenyl-1,2,3-triazole-5-hydrazid (PT) was synthesized by "click chemistry". • A new Schiff base of 1,2,3-triazole (PTSB) was satisfactory for detecting Al3+. • PTSB was applied to image Al3+ in HeLa cells with a lower cytotoxicity. A new compound, 5-methyl-2-phenyl-1,2,3-triazole-5-hydrazid (PT) was designed and synthesized based on "click chemistry". The fluorescence probe 5-methyl-2-phenyl-1,2,3-triazole-5-hydrazid Schiff base (PTSB) was further constructed by a chemical reaction between PT and 4-(diethylamino) salicylaldehyde. PTSB could be used to determine Al3+ in EtOH with high sensitivity and strong anti-interference performance by fluorescence and UV–vis spectroscopic methods. The limit of detection to Al3+ is 5.84 nM and it showed an obvious solvatochromic effect under ultraviolet light. Furthermore, the sensing mechanism of PTSB detecting Al3+ was confirmed in the form of planar structure and 1:1 complexation ratio based on MS, Job's plot, 1H NMR titration, DFT calculation, and the single-crystal structure of PTSB, respectively. PTSB showed less low cytotoxicity to HeLa cells and was successfully used for chromatic bioimaging Al3+ in HeLa cells. It is expected to be developed and utilized as a fluorescence probe for detecting Al3+ in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

• Design of a novel class of Pd-complexes: Pd3 shows unique monodentate-coordination. • Interaction of Pd3 with DNA/BSA was confirmed by experimental and docking study. • Pd3 exhibited anticancer activity with superior selectivity towards cancer cells. • Pd3 induced ROS dependent MOMP decrease leading to cancer cell death. • Cellular uptake of Pd3 was confirmed with fluorescent-based cellular imaging. A novel class of Pd(II) pyrene aroylhydrazone complexes (Pd1–Pd4) of general formula [Pd(L)(PPh 3)Cl] (L = pyrene aroylhydrazones) was synthesized and their solid-state structures were determined by single-crystal XRD study. In vitro cytotoxicity of Pd1 – Pd4 were examined against two cancer cell lines, HeLa and MCF-7 and two non-cancerous cell line, HEK 293T and 3T3-L1 to assess their selectivity. Among these, Pd2 and Pd3 had the most significant cytotoxic effects in comparison to cisplatin, a traditional anticancer medication featuring undesirable side effects, in tested cancer cell lines. Moreover, they showed noticeably less toxicity towards non-cancerous cell lines. Their interactions with serum albumin were confirmed experimentally as well as with molecular docking. Pd3 was also found to effectively interact with DNA as revealed by DNA interactions studies. Pd3 -treated HeLa cells exhibited nuclear apoptotic features such as chromatin condensation and nuclear fragmentation and was also found to induce ROS which further led to decrease in mitochondrial membrane potential in cancer cells. Further, Pd3 was efficiently internalized by HeLa cells as evident from cellular imaging using confocal microscopy. Taken together, we report a novel class of Pd(II) pyrene aroylhydrazone complexes displaying strong protein/DNA binding and anti-cancer activity via ROS generation under in vitro circumstances. Author Statement A.V and M.P conceived the molecular design, synthesis, and characterization. N.S.P.B conceived the single-crystal X-ray diffraction. A.B and S.S carried out the anticancer activity assay. A.V and A.B analyzed the data and wrote the manuscript. S.S and M.P edited the manuscript. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel fluorescent probe TZ-NBD was designed and synthesized for detection of Glutathione (GSH). • The probe TZ-NBD was rapid and sensitive for GSH. • The detection limit was 0.207 μM. • The probe TZ-NBD was demonstrated imaging of GSH in HepG2 cells. Biothiols are significant biomarkers for many diseases. The selective identification of biothiols is very crucial. Herein, we combined phenothiazine and 7-nitrobenzofurazan to form a new fluorescent probe TZ-NBD, due to the difference in response of reactive sulfur species to two fluorophores for distinguishing biothiols specifically. The specificity of TZ-NBD towards biothiols was high and sensitive. Moreover, its detection limit was 0.207 μM for Glutathione (GSH). Finally, TZ-NBD was successfully applied to GSH imaging in HepG2 cells. [Display omitted] [ABSTRACT FROM AUTHOR]

• A D-p-A type probe has been developed for detection of ClO−. • The mechanism associated with oxidation breakage of rhodanine moiety was proposed. • The crystal structure of the probe is reported. • The probe has been successfully applied to the imaging of ClO− in cells, plants and zebrafish. Hypochlorite (ClO−) plays an important role in many cellular processes, which is proved to be related to some serious diseases. Given the electron donating and electron withdrawing properties of benzo[ h ]chromene and rhodanine groups, respectively, we developed a Donor (D)-p-Acceptor (A) type probe 1 for the detection of ClO− based on benzo[ h ]chromene (D) and rhodanine (A), whose structure was determined by ESI-MS, NMR and X-ray diffraction. Probe 1 showed a fast (within 20 s), selective and sensitive response toward ClO− via a fluorescent turn-on output. Based-on the spectral change of probe 1 induced by ClO−, the mechanism associated with oxidation breakage of rhodanine moiety was proposed. Due to the excellent biocompatibility and low cytotoxicity, probe 1 can be used for imaging of ClO− in C6 cells, Arabidopsis thaliana, and zebrafish. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel NTR-responsive "turn off" fluorescent probe TPEDCH-PBN was designed. • TPEDCH-PBN exhibited typical aggregation-induced emission (AIE) properties. • TPEDCH-PBN showed high selectivity and low detection limit towards nitroreductase. • TPEDCH-PBN displayed time-dependent fluorescence quenching behaviors. • The molecular design strategy was elaborated by DFT and docking calculations. Nitroreductase (NTR) is frequently employed as a biomarker to assess the level of hypoxia in tumor tissues. To date, the majority of NTR-reactive probes have focused on the luminescence "turn on" characteristic, which has been plagued by background interferences. In this study, we present the first report of an NTR-responsive "turn-off" fluorescent probe, TPEDCH-PBN, based on AIEgen. This probe exhibits typical aggregation-induced emission (AIE) properties in high PBS fraction, which may be attributed to the restriction of intramolecular motions (RIM) effect. DFT/TD-DFT calculations were employed to determine the discrepancies in structure and electron density distribution among TPEDCH, TPEDCH-PBN OH and TPEDCH-PBN. Additionally, docking calculations were utilized to elucidate the structure-function relationship between the probe and NTR, revealing a favorable structural and spatial match. Photophysical investigations demonstrated the probe's high selectivity towards NTR with the detection limit of 0.68 μg/mL. The dynamic quenching process of TPEDCH-PBN upon NTR was examined, and the quenching constant Ksv was determined to be 53.6 g −1.L. In addition, the NTR detection ability of probe TPEDCH-PBN as well as its time-dependent fluorescence quenching behaviors were confirmed by cell imaging of probe in A549 cells. Overall, this study proposed a novel molecular design approach for the biomarker detection probe, which may prove to be more extensively applicable. Schematic Representation of the NTR-responsive turn-off fluorescent probe based on AIEgen and its bioimaging application [Display omitted] [ABSTRACT FROM AUTHOR]

A new coumarin-based probe 3-acetyl-7-diethylaminocoumarinthiosemicarbazone (DCT) is synthesized for Al3+ fluorescence detection in CH 3 CH 2 OH/H 2 O (6 : 4, v / v). The fluorescence intensity at 428 nm was enhanced about 15-fold with the fluorescence changed from colorless to blue. The binding constantof Al3+ with DCT is 5.04 × 106 M−1. The limit of detection (LOD) of Al3+ is calculated to be 82 nM. Furthermore, the binding details are determined by Job's plot and ESI - MS studies, which indicated that a stoichiometric ratio of 1 : 1 complex is formed between Al3+ and DCT. Cell imaging confirmed that DCT could useful for detecting Al3+ in HepG2 cells. • Probe DCT is highly selective and sensitive towards Al3+in aqueous solution phase with LOD is 82 nM,which could monitor intracellular Al3+ levels. • The mechanism indicated that a ratio of 1 : 1 complex is formed between Al3+ and DCT. [ABSTRACT FROM AUTHOR]

A rhodamine B-based chromo-fluorogenic probe BOS is prepared with a good yield by condensating an o-diaminobenzene functionalized rhodamine derivative (RBO) and a large steric hindrance salicylaldehyde, and characterized by elemental analysis, infrared spectroscopy (IR), 1H and 13C NMR technology, and high resolution mass spectrum (HRMS). Spectroscopy experiments reveal that the probe can selectively and sensitively detect Al3+ from a variety of metal ions with a low detection limit of 1.855 μmol/L. Compared to traditional detection methods, BOS provides an inexpensive, rapid and straightforward way for Al3+ detection that can be distinguished by "naked eye". The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2- H - tetrazoliubromide) assays and cell imaging experiments demonstrate that the sensor is low toxic and amicable for Al3+ sensing in living cells. Image 1 • A novel rhodamine-based probe BOS is designed and synthesized. • BOS is able to high selectively and sensitively detect Al3+. • The detection process can be identified through naked eye. • BOS is capable of detecting Al3+ in complex biological environment. [ABSTRACT FROM AUTHOR]

• A novel fluorescence sensor (TCS) for Pd2+ was designed and synthesized. • TCS exhibited selective sensing abilities for Pd2+ among various metallic ions. • The detection limit for Pd2+ was as low as 4.32 × 10−8 M. • The sensing mechanism of 1:1 stoichiometry ratio was confirmed. • TCS displayed good bioimaging performance on Pd2+ detection in living system. Although some Pd2+ sensors were presented, the in-situ and real-time examination of Pd2+ based on fluorescent sensor is still a challenging task. In this work, a novel thiourea-cyanostilbene derivative (TCS) was designed and synthesized as the effective fluorescent sensor on in-situ and real-time sensing Pd2+ in aqueous media. TCS possessed good AIE fluorescence in THF/H 2 O solution. The fluorescence was selectively quenched by Pd2+ among all kinds of metallic ions. The sensing mechanism of 1:1 stoichiometry ratio for TCS with Pd2+was confirmed by Job's plot, 1H NMR and MS spectra. The detection limit was as low as 4.32 × 10−8 M. TCS exhibited the good sensing application for Pd2+ in tested paper and simulated samples with low errors. TCS had the excellent fluorescence imaging performance in living cells with the fluorescence imaging response on Pd2+. This research not only reported an effective fluorescence sensor for Pd2+, but also suggested the good application prospect on in-situ and real-time sensing Pd2+ in complicated environment. [ABSTRACT FROM AUTHOR]

• Selective colorimetric response of 2-Hydroxybenzhydrazone based probe with Cu2+. • Probe demonstrated high selectivity and sensitivity for Fe2+ ion fluorimetrically. • Naked eye sensor for Cu2+. • Found useful for in vivo detection and imaging of Fe2+. • Application of the probe in paper strips and logic gate for detection of metal ions. 2-Hydroxybenzhydrazone based probe HNN demonstrated highly selective sensing ability towards Cu2+ and Fe2+ ion through colorimetric and fluorimetric methods respectively. The probe can be used as a "naked-eye" sensor based on its color change from almost colorless to bright yellow (for Cu2+) and pale yellow (for Fe2+). The colorimetric detection of Cu2+ involved enhancement in internal charge transfer (ICT). In the detection of Fe2+ through fluorescence, combined effect of restricted photo-induced electron transfer (PET) and paramagnetic nature of Fe2+ played major role. Job's plots based on absorption (Cu2+) and fluorescence (Fe2+) data along with mass spectral studies indicated 1:1 stoichiometry of metal to HNN in the complex. The binding of the probe HNN with both the metal ions was found chemically reversible by adding EDTA. Experimental observations on binding of the probe with metal ions were corroborated with density functional theory (DFT). The effect of pH and response time in sensing was also determined. The probe was found useful for in vivo detection and imaging of Fe2+ in MDA-MB-231 cells. Paper strips of the probe were made and used for naked-eye detection of Cu2+. The probe was also used in the construction of logic gate for detection of Cu2+and Fe2+. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel NIR colorimetric-fluorescence probe was prepared for detection of hydrogen sulfide. • The probe showed rapid, specific and sensitive detection of hydrogen sulfide with a large Stokes shift. • The probe was capable of imaging hydrogen sulfide in living cells and mice. We presented here a novel near-infrared fluorescent probe based on 2-(2′-hydroxyphenyl)benzothiazole -dicyanoisophorone as fluorophore and 2,4-dinitrobenzenesulfonyl moiety as detection functionalized group for the discrimination of hydrogen sulfide (H 2 S). Probe L exhibited good specificity and sensitivity "turn on" response at 720 nm with a large Stokes shift (155 nm), rapid response (< 60 s) and low detection limit (3.15 × 10−7 M), which also could be identified by the naked eyes. Moreover, probe L was successfully used to image exogenous/endogenous H 2 S in cells and mice, which demonstrated its potential applications in living systems. A novel fluorescein based on 2-(benzo[ d ]thiazol-2-yl)phenol-dicyanoisophorone probe was constructed for the discrimination of hydrogen sulfide. The probe was applied for the rapid, sensitive, large Stokes shift, colorimetric and large near-infrared fluorometric determination of H 2 S, based on the displacement approach. The low cytotoxicity and excellent imaging performance was successfully applied for mitochondrial localization in living cells and endogenous and exogenous H 2 S detection in vivo. [Display omitted] [ABSTRACT FROM AUTHOR]

• Twenty four novel benzo[ cd ]indol-2(1 H)-one-donepezil hybrids were designed and synthesized. • Compound 6a exhibited the strongest inhibitory activity against AChE with an IC 50 value of 0.16 μM. • Kinetic analyses and molecular modeling studies indicated that compound 6a had a mixed-type inhibition for AChE. • Compound 6a demonstrated no obvious cytotoxicity and could be used in imaging living SH-SY5Y cells. A novel series of benzo[ cd ]indol-2(1 H)-one-donepezil (BIO-DPZ) hybrids (5a-m, 6a-k) was designed, synthesized and evaluated as cholinesterase inhibitors and living cell imaging agents. These compounds were potent inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Compound 6a exhibited the strongest inhibitory activity against AChE with an IC 50 value of 0.16 μM. Compound 6i had the strongest inhibition of BuChE with an IC 50 value of 5.37 μM. Kinetic and molecular modeling studies showed that 6a bound both catalytic active site and peripheral anionic site of AChE. Compounds 6a and 6i both showed lower SH-SY5Y, HepG2 and HL-7702 cytotoxicity than the mitoxantrone. Promisingly, the most active compound, 6a, was successfully used in living SH-SY5Y cell imaging and had predictable lipophilicity and blood-brain-barrier permeation properties. These hybrids should undergo further systematic study in the treatment of Alzheimer's disease. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract A novel Schiff-base, [9-(2-Chloro-ethyl)-9H-carbazol-3-yl-methylene]-(9-ethyl-9H-carbazol-3-yl)-amine (CECA) was designed and synthesized, which was highly selective and sensitive for the detection of Al3+ by colorimetric, ultraviolet absorption and fluorescence three-signal methods. The detection limit was evaluated to be as low as 74 nmol/L for the ultraviolet absorption method and 19 nmol/L for fluorometric method. These three methods could determine qualitatively and quantitatively the concentrations of Al3+ and been used in different conditions. The mechanism was explored that the double bond (C N) of CECA was broken to form the carbazole aldehyde and carbazole amine complex accompanied by fluorescence enhancement by the Job's plot, 1 H NMR , the electrospray ionization mass spectra (EI-MS) and fluorescence methods. More significantly, the fluorescence imaging showed that CECA could detect Al3+ in living cells. Graphical abstract A colorimetric, ultraviolet absorption and fluorescence three-signal probe based on bis-carbazole for Al3+ detection was designed and synthesized. The combined model between CECA and Al3+ was successfully deduced. More significantly, CECA was successfully applied to Al3+ detection in living cells by confocal imaging. Image 1 Highlights • A simple three-signal probe has been developed. • The combined model between probe and Al3+ was successfully deduced. • The probe detected successfully Al3+ in living cell. [ABSTRACT FROM AUTHOR]

• A simple method is utilized to produce N-doped carbon dots (N CDs) from o-aminophenol and ethylenediamine. • The N CDs possess quantum yield up to 38.4%. • Owing to the highly sensitive response to Ag+, the prepared N CDs can be developed as an effective sensing platform. • The N CDs are also used in bioimaging. N-doped carbon dots (N CDs) with green fluorescence is developed by the hydrothermal reaction with o-aminophenol and ethylenediamine as carbon and nitrogen sources, and the quantum yield (QY) is 38.4%. The N CDs are characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible absorption spectroscopy (UV–vis) and fluorescence spectroscopy. The results show that N CDs have good fluorescence properties and stability, and the N CDs are further utilized as a sensor for Ag+ via the static quenching effect (SQE) (λ ex =430 nm, λ em =510 nm). The linear range of Ag+ is 30–210 µmol/L with a limit of detection (LOD) of 4.7 µmol/L (S/ N = 3). On this basis, we quantitatively detect Ag+ in real samples. Furthermore, due to the excellent fluorescence performance, the N CDs are found to be an effective tool for Ag+ sensing in bioimaging. Herein, green-emission fluorescent N-doped carbon dots (N CDs) are developed by the hydrothermal reaction of o-aminophenol and ethylenediamine, and the quantum yield (QY) is 38.4%. The N CDs are utilized as a sensor for Ag+, and the linear range is 30–210 µM with a limit of detection (LOD) of 4.7 µM (S/ N = 3). On the other hand, the N CDs are further applied to biological imaging, constructing the fluorescence analysis method of Ag+ in biological samples. [Display omitted] [ABSTRACT FROM AUTHOR]

• The newly synthesized 5′-(1H-phenanthro[9,10- d ]imidazol-2-yl)-[2,2′- bithiophene ]−5-carbaldehyde was fully characterized by the optical and biological properties. • The demonstration of the high affinity of IA-2 to the protein based on the AutoDock simulation and the low toxicity, good bioavailability and low bioaccumulation in the tissues of living organisms allowed for experimental studies with the use of cell lines. • IA-2 was successfully used for staining cells fixated with formaldehyde and methanol. This paper presents the synthesis as well as the linear and non-linear optical properties of the new phenathroimidazole derivative, 5′-(1 H -phenanthro[9,10- d ]imidazol-2-yl)-[2,2′- bithiophene ]-5-carbaldehyde. Detailed analysis of optical and electrochemical properties showed the possibility of using the newly synthesized compound as a fluorescence probe in bioimaging. For this reason, the chemical analysis was supplemented with a biological study, showing a high affinity for protein, easy conjugation with biomolecules, and no toxicity to living organisms. The presented compound was tested in fixated and live cell imaging. In addition, the experimental research was supplemented with quantum-chemical simulations. [Display omitted] [ABSTRACT FROM AUTHOR]

Three unprecedented triphenylamine-based D-A type terpyridine derivatives ( TriphenL1-TriphenL3 ) with different positions of nitrogen atom in the terpyridine moiety were carefully designed and fully characterized, which was further confirmed via single-crystal X-ray diffraction determination. The photophysical properties of all the three compounds were comprehensively studied by both theoretical calculations and experimental techniques, which revealed that TriphenL3 with γ-pyridine in the NIR region possessed large two-photon absorption cross-section. Experiments including photophysical tests and cytotoxicity demonstrated these dyes were characterized with larger Stokes shifts, longer fluorescence lifetime, low toxicity and good cell penetrability, thus TriphenL1-TriphenL3 were succeed to be devoted as cell stains, suggesting a prospect for applications of in vitro and vivo cellular imaging. [ABSTRACT FROM AUTHOR]

• Probe LD-HJZ2 with deep-red emission was developed for imaging LDs within a short time via a wash-free procedure. • Probe LD-HJZ2 showed obviously aggregation-induced emission (AIE) behavior. • The photophysical properties of these two probes were systematically investigated combining with theoretical calculation. In this work, we constructed two novel fluorescent probes based on coumarin derivatives for imaging lipid droplets. The photophysical properties indicated that probe LD-HJZ1 exhibited an aggregation-caused quenching (ACQ) feature, while probe LD-HJZ2 showed obviously aggregation-induced emission (AIE) behavior. In addition, the maximum emission wavelength of probe LD-HJZ2 was localized around 687 nm with 90% water content. Cell imaging experiments demonstrated that the fluorescence images of probes LD-HJZ1 and LD-HJZ2 were overlapped well with the commercial lipid droplet dyes. Interestingly, probe LD-HJZ2 was capable of targeting lipid droplets within a short time (< 1 min) with or without wash-free procedure. Furthermore, probe LD-HJZ2 could be used to detect the changes in the number of lipid droplets under starvation conditions and oleic acid stimulation. This work provides a new perspective for the development of fluorescent probes with deep-red emission for targeting lipid droplets. [ABSTRACT FROM AUTHOR]

• We have prepared N-doped C-dots from Vitis vinifera plant extract. • The synthesized N-doped C-dots exhibit, the green fluorescence. • We found higher antimicrobial activity in N-doped C-dots. • N-doped C-dots have utilized as antimicrobial activity for the inhibition of human pathogens. • The antimicrobial activity of N CDs was performed on different concentration, highly performed in 100 µg/mL−1. The synthesised N CDs were derived from Vitis vinifera boll and it's prepared in one pot hydrothermal process. The V.vinifera derived N CDs were as exhibit the emission is (λ ex = 380 nm and λ em = 460 nm) green fluorescence. The synthesized N CDs was preliminarily characterised by UV–vis spectroscopy, it shows the two peaks at 277 nm and 322 nm. The FT-IR and high resolution XPS was confirmed by their functional group of N CDs. The Raman spectroscopy and XRD also confirms the N CDs are graphitic in nature. Finally N CDs were applied in vitro antimicrobial study in gram positive and negative bacteria. Among the results of antimicrobial activity is shown in Minimum inhibitory concentration of the N CDs is 25 to 100 µg mL−1 respectively in different bacteria. The highest concentration of the100µg mL−1 was performed in Klebsiella Pneumoniae is zone of inhibition is 14.8 ± 1.12. [ABSTRACT FROM AUTHOR]

• Dicarboxylato bridged Zn(II) Coordination Polymer chelated with 4′-Chloro-2,2′:6′,2′′-terpyridine is characterised. • Noncovalent interactions (Cl—Cl, C-H—π, π⋅⋅⋅π) make 3D superstructure • Upon binding with Al3+ the fluorescence enhancement of the CP is recorded. • LOD (0.2 µM) is far below the EPA recommended data (7.4 µM) and method is used in real water sample analysis. • Intracellular Al3+ is determined in MDA-MB 231 cells by adding CP using Fluorescence imaging microscope. Recently, coordination polymers (CPs/MOFs) have emerged as a desirable hybrid material for sensing analytes- such as ions, amino acids, nitroexplosives due to their versatility, stability, reusability, economic benefits and sustainability. Herein, [Zn(bdc)(4-Cltpy)(H 2 O)] n (CP) [4-Cltpy = 4′-Chloro-2,2′:6′,2′′-terpyridine, H 2 bdc = Benzene-1,4-dicarboxylic acid], a coordination polymer, is structurally characterized. The structure reveals that the bdc2− bridges Zn(II) via dicarboxylato-O and propagates to form a 1D Coordination Polymer. The 1D CP further undergoes Cl⋯Cl interaction to form a 2D sheet and H-bonding and π⋅⋅⋅π interactions help to construct a 3D supramolecular architecture. Photoluminescence study exposes that the CP is weakly emissive while the fluorescence intensity is significantly enhanced upon interaction with Al3+ in aqueous medium even in presence of quenchable ions like Fe3+ and Cr3+. The detection limit (LOD) is 0.2 ± 0.005 µM (3σ/M method) which is much lower than the permissible limit in drinking water recommended by U.S. Environmental Protection Agency (0.2 mg/L or 7.4 µM). The toxicity of CP has been checked by MTT Assay and intracellular imaging of Al3+ is vivid in human breast cancer MDA-MB 231 cells. The reagent is used for real water sample analysis by fluorescence spectroscopic technique. [Zn(bdc)(4-Cltpy)(H 2 O)] n (CP) [4-Cltpy = 4′-Chloro-2,2′:6′,2′′-terpyridine, H 2 bdc = Benzene-1,4-dicarboxylic acid] forms a 3D superstructure through coordination and noncovalent interactions. The coordination polymer shows turn-on fluorescence sensing to Al3+ out of 17 ions in aqueous medium with a detection limit (LOD), 0.2 µM. The CP is nontoxic to 100 µg and helps intracellular imaging of Al3+ in MDA-MB 231 cells. [Display omitted] [ABSTRACT FROM AUTHOR]

• A simple way to synthesize probes. • A new fluorescent probecan detect the level of ClO− in aqueous solution quickly and sensitively. • A new probe can be used to monitor the level of ClO- in living cells. Hypochlorite (ClO−) plays an important source of chlorine contaminant in the environment which may cause various diseases. Therefore, it is imperative to explore a novel method for instant detection of ClO−. In this research, a new fluorescent probe (JSJ-1) has been designed and synthesized for selective response toward ClO−. The response time is less than 30 s while the detection limit can reach as low as 52.3 nM. Further experiments showed that JSJ-1 retains excellent anti-interference features when a variety of possible interferent anions or cations coexist and therefore displayed successful application in ClO− detection in environmental water samples. In addition, the working principle of the probe JSJ-1with high sensitivity and specificity is based on the oxidative cleavage of olefin units by ClO−. The explanation for the chemical processes is supported by fluorescence spectra, UV-vis spectra, 1H NMR, HRMS, and density functional theory (DFT) calculations. A new fluorescent probe JSJ-1 can detect the level of ClO− in aqueous solution quickly and sensitively. [ABSTRACT FROM AUTHOR]

• A new mitochondria-targeted fluorescent probe ZZY for the reversible recognition of SO 2 and FA was developed. • Probe ZZY showed good spectral performance for the reversible recognition of SO 2 and FA. • Probe ZZY exhibited low cytotoxicity and could be used to image SO 2 and FA reversibly in mitochondria. Sulfur dioxide (SO 2) and formaldehyde (FA) are the main contaminants emitted by factories and their interaction could produce secondary organic aerosols which are harmful to human health. In biological systems, SO 2 and FA levels are closely associated with many biological diseases. To explore the specific functions played by SO 2 and FA in vivo, a new fluorescent probe ZZY that can reversibly recognize SO 2 and FA in mitochondria was devised and synthesized. Probe ZZY showed advantages of great selectivity, good sensitivity and low cytotoxicity and the detection limit is 0.447 μM of SO 2. In addition, probe ZZY could reversibly recognize SO 2 and FA. More importantly, the probe showed good biocompatibility and could successfully perform reversible imaging of SO 2 and FA in mitochondria of living cells. [Display omitted] [ABSTRACT FROM AUTHOR]

• Ovarian cancer is the third leading gynaecological malignancy that leads to death in females annually. • The FDA approved drug from both generic and pharmaceutical brands but these synthetic compounds have many adverse effects. • Our in silico analysis suggest that dihydroquercetin (DHQ) is an effective herbal compound that is druggable, and leadlike. • DHQ has good bioavailability, medicinal chemistry with a higher solubility with no adverse side effects, and toxicity. • Our in vitro study on SK-OV-3 cell lines showcased that DHQ caused apoptosis at 250 µm. Ovarian cancer is the third leading gynaecological malignancy that leads to death in females annually. According to the GLOBOCAN 2020 incidence cases in Asia, there were a total of 100,854 ovarian cancer incidence cases. The Food and Drug Administration (FDA) has approved some drug compounds from both the generic and pharmaceutical brands for ovarian cancer, however, these synthetic compounds have many adverse effects such as – infections, fatigue, nerve problems, alopecia (hair loss), weight loss, lack of appetite, chemobrain (forgetfulness). By exploring both the in silico and in vitro aspects, we suggest that dihydroquercetin (DHQ) or simply taxifolin is an effective herbal compound that is druggable, leadlike, has good bioavailability, medicinal chemistry with a higher solubility with no adverse side effects, and toxicity. It also showcased a greater and more stable binding affinity and energy landscape with target POTEE with minimal energy frustrations and clashes. Our study also was able to predict a positive classification model of DHQ with a Tanimoto-distance threshold (d 0 = 0.8) and smoothing factor (h = 0.9). We observed that the accuracy decreases to 90% from 100% at distance = 0.7, predicted number of compounds rose from 80 to 95%, which can be worth the loss of accuracy. Furthermore, our in vitro analysis on SK-OV-3 cell lines showcased that the anticancerous activity of DHQ caused significant cancer cell death and cell proliferation at 100 µm and 250 µm solutions. The DHQ drug dosages were further verified by Calcein-AM-PI live dead cell imaging on both concentrations. We observed that at 250 µm, DHQ caused apoptosis in SK-OV-3 cells. Hence, it is concluded that DHQ reduces ovarian cell proliferation and eventually cell death (apoptosis) in ovarian cancer. [Display omitted]. [ABSTRACT FROM AUTHOR]

• A novel quinoline-fluoran hybrid fluorescent dye QF has been easily prepared. • A copper ion-selective fluorescent probe QFH has been developed based on QF. • QFH shows good performance in tracing intracellular copper ions by fluorescence imaging. Developing fluoran dyes as fluorescent probes is interesting because it is of great significance to extend their applications from the printing industry to other fields such as fluorescence analysis and medicine. We here present a new quinoline-fluoran hybrid dye QF , which delivers fluorescent signals in water (pH: 4.0 - 9.0) with the maximum absorption and emission centered at 514 nm and 597 nm, respectively. In addition, a large Stokes shift (83 nm) can be observed when compared to that of rhodamine B. QF is further employed for the preparation of a new fluorescent probe QFH , which exhibits high selectivity towards copper ions with the limit of detection down to 1.54 nM via a Cu2+-triggered spirolactam ring opening and hydrolysis process. Significantly, QFH can be applied for the detection of copper ions at physiological pH conditions (pH: 6.0 - 9.0) and shows low cell cytotoxicity, which allows it to be a candidate for tracing Cu2+ by cell imaging. A novel quinoline-fluoran hybrid fluorescent probe for copper ion-selective detection and application in cell imaging. [Display omitted] [ABSTRACT FROM AUTHOR]

The selective fluorescence zinc(II) sensing properties of a Schiff-base compound, 2-methoxy-6-(2-morpholinoethyliminomethyl)phenol (HL) have been explored. The emission intensity of HL in the presence of one equivalent of Zn 2+ ion increases by about 25 times. Several other metal ions, except Cd 2+ and Ni 2+ , have not been able to increase the emission intensity of HL significantly. The quantum yield and life-time of HL have also been increased in the presence of Zn 2+ ions. The enhancement in fluorescence intensity of HL is mainly due to the restriction of ESIPT, CHEF and PET on complex formation. HL forms a complex with Zn 2+ in 1:1 ratio as evidenced by Job's plot analysis and X-ray single crystal structure determination. Some theoretical calculations have been performed to get a better view on the nature of the observed electronic transitions. The probe has been applied for imaging of DLD-1, human colorectal adenocarcinoma cell. [ABSTRACT FROM AUTHOR]

• Synthesis of conjugated probe TPAQ-H 2 O 2 with positive nitrogen ion. • TPAQ-H 2 O 2 realized H 2 O 2 detection with higher sensitivity, fast response time (within 3 min). • The probe was successfully applied for mitochondrial co-localization experiments to image endogenous and exogenous H 2 O 2. Herein, a novel reactive H 2 O 2 fluorescent probe TPAQ-H 2 O 2 based on triphenylamine derivatives was prepared to detect H 2 O 2 in vivo and in vitro. Due to the H 2 O 2 -triggered the effective chemical conversion of the quinoline salt group cleavage, probe TPAQ-H 2 O 2 exhibited an intense Stokes shift (239 nm), exhibited high selectivity (LOD= 2.5 µmol) and quick response to H 2 O 2 in DMSO/PBS buffer (4/6, v/v) solution in the presence of other competing substances (such as K+, Ca2+, Na+, Mg2+, Fe3+, CO 3 2−, HS−, SO 4 2−, F−, AcO−, NO 3 −, NO 2 −, ONOO−, NO, O 2 −, GSH, Cys, Hcy, NaClO). Benefiting from its excellent sensing properties, the probe TPAQ-H 2 O 2 has been used in mitochondrial co-localization experiments to image endogenous and exogenous H 2 O 2. In addition, due to its excellent water solubility, the probe TPAQ-H 2 O 2 can also provide a new fluorescent detection idea to detect H 2 O 2 in real samples. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new AIEgene based dicyanoisophorone derivative has been synthesized. • The AIEgen exhibits strong red emission in solid-state. • The AIEgen exhibits nonlinear absorption property and two-photon fluorescence. • Living cells imaging with 900 nm excitation was obtained with the AIEgene. A dicyanoisophorone derivative (1) with a D-π-A structure has been synthesized. 1 displayed characteristic of intramolecular charge transfer (ICT) and exhibited very weak fluorescence in solvents (ϕ f ≤ 0.01) but strong red fluorescence in solid-state (ϕ f = 0.45). Mechanism demonstrated that the strong emission in solid state resulted from aggregation-induced emission (AIE). Furthermore, 1 exhibited a strong two-photon fluorescence in solid-state and a bright two-photon fluorescence imaging in live cells was obtained upon irradiation with 900 nm fs laser. [ABSTRACT FROM AUTHOR]

• A near infrared AIE probe for visualization of ClO−and LDs at the cellular level. • Specifically recognize ClO− with high sensitivity, large Stokes shift. • The reaction between the T and ClO− was accelerated by loading the probe with protein. Both of lipid droplets (LDs) and hypochlorous acid/hypochlorite (HClO/ClO−) play important roles in regulating cell metabolism and maintaining normal operation of life activities. Here, we report the synthesis of probe T, which is a typical compound with AIE properties. The probe T can not only detect ClO− by proportional fluorescence, but also specifically target LDs. T displayed an excellent spectral performance with a long emission wavelength (715 nm), large stokes shift (211 nm), wide pH response range. When it encountered ClO−, the fluorescence color changed from red to blue with a large fluorescence signal shift (from 715 nm to 430 nm) and good sensitivity (detection limit: 0.102 μM). More interestingly, we successfully advanced the response speed of T to ClO− by loading the AIE probe with protein. Additionally, cell imaging experiments demonstrated that T was perfectly utilized to visualize exogenous/endogenous ClO− in cells and possessed an excellent LDs-targeting ability. [Display omitted] [ABSTRACT FROM AUTHOR]

• A oxazole-based NIR fluorescent probe has been developed for the sequential detection of Cu2+ and S2− ions. • The probe ISOP has an excellent specificity for Cu2+ and a low detection limit (0.36 µM). • The probe can detect Cu2+ by liquid and solid colorimetry and has been successfully applied to live cell imaging. In this study, we reported a novel oxazole-based NIR probe for the detection of Cu2+ and S2− ions sequentially in buffer solution. The probe showed a "turn-off" fluorescent response towards Cu2+ ion with a large Stokes' shift, accompanied with the solution color changes from bright red to colorless. The bonding mechanism was proposed based on by fluorescent and UV-Vis titrations, 1H NMR titrations and theoretical calculation studies. Moreover, the resulting ISOP-Cu2+ complex could detect S2− by "turn-on" fluorescent response. Furthermore, the probe has been successfully used in liquid colorimetry and solid filter paper colorimetry, as well as live cell imaging. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of new Naphtalimide-BODIPY dyad systems. • Investigation of photophysical properties. • The use of NI-BODIPYs for live cell lines is demonstrated by flow cytometry and confocal microscopy. • The antimicrobial activities of dyads were evaluated on Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Naphthalimide-Borondipyrromethene (NI-BODIPY) dyads, bearing NI unit on the meso and styryl positions of BODIPY core were designed and subjected to photophysical, in vitro cell imagining and antimicrobial activity studies. The identities of synthesized compounds (3 - 5) were confirmed by using FT-IR, 1H, 13C NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The structure of the NI-BODIPY dyad (3) was also characterized by means of X-ray diffraction. Spectroscopic properties of dyad systems were explored in detail via UV-vis absorption and fluorescence emission spectroscopies. Mono- and distyryl- derivatives (4 and 5) revealed a substantial conjugation effect manifested by an expected bathochromic shift in absorption and emission spectra relative to dyad 3. The use of NI-BODIPYs for live cell lines is demonstrated by flow cytometry and confocal microscopy in which compound 3 produced the brightest fluorescence in confocal microscopy. Furthermore in vitro antimicrobial activities were evaluated on Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Noticeably, the distyryl- derivative 5 functionalized with three NI units displayed superior antibacterial activity against both E. coli and S. aureus with MIC values of 76 and 110 μM, respectively. Naphthalimide decorated BODIPY dyads have been proposed as both antibacterial and cell imaging agents. [Display omitted] [ABSTRACT FROM AUTHOR]

• 2, 4-dinitrophenyl hydrazine based Schiff-base (L) was synthesized. • The fluorescence of L corresponds to excited state intra-molecular proton transfer (ESIPT) emission. • The intriguing chemo-sensing properties of L were evaluated by fluorescence studies. • The L-Zn2+ complex formation is reversible upon addition of strong chelating agent EDTA. • The probe L is highly selective for Zn2+ in DMSO-H 2 O and living Hela cell. • The probe L is the first molecule, which is highly selective sensor for Zn2+ in solid phase. Luminescent chemosensors based on Schiff bases have drawn tremendous research interest owing to their easy synthesis, enriched photophysical properties, and potential applications in biology and materials science. A dinitrophenyl-based Schiff base molecular probe (L) was synthesized and characterized to estimate its selective detection of Zn2+. The probe L exhibits weak emission in the DMSO-H 2 O solvent mixture due to excited-state intramolecular proton transfer (ESIPT). Interestingly, fluorescence is enhanced with the addition of Zn2+ to the DMSO-H 2 O solution of L , whereas the emission remains unchanged with the addition of other ions. This specifies that probe L acts as a selective chemosensor for Zn2+. The binding stoichiometry for the L : Zn2+ complex is 1:1, which was calculated using the Benesi-Hildebrand plot from fluorescence data. Furthermore, the binding modes are also supported by density functional theory (DFT) calculation. The binding constant and detection limits are 6.35 × 107 M−1 and 1.1 × 10−8 M, respectively. The L-Zn2+ complex formation is reversible upon the addition of a strong chelating EDTA ligand. In addition, L is also used to detect Zn2+ in living Hela cells and selective sensing of Zn2+ in the solid phase. [Display omitted] [ABSTRACT FROM AUTHOR]