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Organic corrosion inhibitors (OCI) have been widely accepted as a reliable method for enhancing the durability of marine reinforced concrete structures. However, the effect of OCI on steel corrosion is not clear in the case of cracks appearing in the concrete cover. In this paper, steel corrosion behaviors in cracked concrete with different crack widths, intact concrete containing OCI, and cracked concrete containing the OCI exposed to the marine tidal zone were investigated through open-circuit potential tests and EIS measurements. The obtained results illustrate that the corrosion rate of steel in cracked concrete is reduced with the decrease of crack width having an initial width of less than less than or equal to 200 μm in the marine tidal zone. Based on the Rf and Rct values, it is found that the alcohol amine-based OCIs can improve the corrosion resistance of steel in intact concrete and concrete with microcracks (with a width of less than 100 μm) exposed to the marine tidal zone. The carboxylic acid-based OCIs aggravate the steel corrosion due to the hydrophobicity provided by carboxylic acids for seawater transport through cracks. The ester-based OCIs also increase the steel corrosion rate as it accelerates concrete carbonation. [ABSTRACT FROM AUTHOR]

Background: The development of wearable health monitoring systems is garnering tremendous interest in research, technology and commercial applications. Their ability of providing unique capabilities in continuous, real-time, and non-invasive tracking of the physiological markers of users can provide insights into the performance and health of individuals. Electrocardiogram (ECG) signals are of particular interest, as cardiovascular disease is the leading cause of death globally. Monitoring heart health and its conditions such as ventricular disturbances and arrhythmias can be achieved through evaluating various features of ECG such as R-peaks, QRS complex, T-wave, and P-wave. Despite recent advances in biosensors for wearable applications, most of the currently available solutions rely solely on a single system attached to the body, limiting the ability to obtain reliable and multi-location biosignals. However, in engineering systems, sensor fusion, which is the optimal integration and processing of data from multiple sensors, has been a common theme and should be considered for wearables. In recent years, due to an increase in the availability and variety of different types of sensors, the possibility of achieving sensor fusion in wearable systems has become more attainable. Sensor fusion in multi-sensing systems results in significant enhancements of information inferences compared to those from systems with a sole sensor. One step towards the development of sensor fusion for wearable health monitoring systems is the accessibility to multiple reliable electrophysiological signals, which can be recorded continuously.Results: In this paper, we develop a textile-based multichannel ECG band that has the ability to measure ECG from multiple locations on the waist. As a proof of concept, we demonstrate that ECG signals can be reliably obtained from different locations on the waist where the shape of the QRS complex is nearly comparable with recordings from the chest using traditional gel electrodes. In addition, we develop a probabilistic approach-based on prediction and update strategies-to detect R-peaks from noisy textile data in different statuses, including sitting, standing, and jogging. In this approach, an optimal search method is utilized to detect R-peaks based on the history of the intervals between previously detected R-peaks. We show that the performance of our probabilistic approach in R-peak detection is significantly better than that based on Pan-Tompkins and optimal-threshold methods.Conclusion: A textile-based multichannel ECG band was developed to track the heart rate changes from multiple locations on the waist. We demonstrated that (i) the ECG signal can be detected from different locations on the waist, and (ii) the accuracy of the detected R-peaks from textile sensors was improved by using our proposed probabilistic approach. Despite the limitations of the textile sensors that might compromise the quality of ECG signals, we anticipate that the textile-based multichannel ECG band can be considered as an effective wearable system to facilitate the development of sensor fusion methodology for pervasive and non-invasive health monitoring through continuous tracking of heart rate variability (HRV) from the waist. In addition, from the commercialization point of view, we anticipate that the developed band has the potential to be integrated into garments such as underwear, bras or pants so that individuals can use it on a daily basis. [ABSTRACT FROM AUTHOR]

Although studies on water-repellent properties of silicon resin (SR) on cement-based materials have received tremendous attention around the world in recent years, they mainly focus on individual properties of water-repellent concrete treated with SR such as strength and water permeability resistance. However, to date, a systematic and comprehensive investigation is missing. The current study therefore investigates the influence of SR on the durability properties of cementitious materials by adding SR emulsion into integral concrete mixture and coating concrete surface with SR. The microscopic and mechanical properties and the durability performance were tested on the integral SR water‐repellent concrete (C-ISR) and SR surface water-repellent concrete (C-SSR). The obtained results indicate that SR application has no impact on hydration reaction and corresponding composition of cement-based materials, while SR addition leads to a reduction in strength and early shrinkage of cement mortar because the added SR delays the hydration reaction. Water-repellent treatment via SR can significantly reduce the water permeability of concrete, which is more apparent for surface water-repellent treatment (SSR). Furthermore, the durability properties were investigated, and the results indicate that integral SR water-repellent treatment (ISR) possesses better properties than SSR, which suggests water-repellent treatment via surface coating as an effective means to improve concrete durability. [ABSTRACT FROM AUTHOR]

• Effects of organic corrosion inhibitors on steel corrosion under chloride attack are studied. • Alcoholamines significantly enhance the passive film resistance of steel. • Carboxylic acids can replace the chloride ions attached to the steel surface. Organic corrosion inhibitors (OCIs) are commonly used to enhance reinforced concrete durability in the marine environment. In this contribution, the effects of OCIs on steel corrosion in concrete exposed to coupled deterioration of freeze–thaw cycles and chloride attack have been evaluated. Concrete samples with mild steels were mixed with three commonly used OCIs (alcoholamines-, carboxylic acids-, and esters-based), and exposed to freeze–thaw cyclic test in a 3% NaCl solution. The corrosion-resistance mechanisms of OCIs on steel corrosion were revealed using the open circuit potential test (OPC) and electrochemical impedance spectroscopy measurement (EIS). The steel–concrete interface micromorphology was observed by the optical microscope and the scanning electron microscope (SEM). The results showed that salt-frost resistance of concrete incorporated with alcoholamines-, carboxylic acids-, and esters-based OCIs was improved by about 50%, 350% and 200%, respectively. However, internal damage caused by freeze–thaw cycles was aggravated after adding easter-based OCIs due to the reduction in pore diameter caused by hydrophobic calcium salt lining. Alcoholamines- and carboxylic acids-based OCIs could significantly delay the steel de-passivation. Alcoholamines could increase the passive film resistance and carboxylic acids could replace the chloride attached to the steel surface. [ABSTRACT FROM AUTHOR]

• The self-healing mechanism of concrete cracks exposed to the tidal zone is studied. • The crack width was monitored during marine exposure. • Hydration and carbonization are vital self-healing mechanisms for small cracks. • Brucite and calcite are the main self-healing products in cracks wider than 100 μm. The autogenous self-healing of cracks can reduce the risk of ingress of aggressive substances into concrete. Although autogenous self-healing mechanisms of concrete have been studied by simplified simulation experiments in the laboratory, few investigations have been carried out in the actual environment. This paper presents the autogenous self-healing mechanism of cracked concrete exposed to the marine tidal zone. The phases shown in the self-healing products were quantified by X-ray diffraction (XRD) and thermogravimetry-differential thermogravimetry (TG-DTG). The micromorphology of the self-healing products and elemental distribution in cracks were studied by SEM. The results show that the self-healing efficiency and composition of self-healing products are highly dependent on the crack width. For 50 and 100 μm cracks, the crack closure rate is 84% and 73%, respectively. Regarding 200 μm cracks, the average crack width is reduced, but partial self-healing of the crack is not observed. Cracks wider than 350 μm are increasingly enlarged due to spalling caused by the physical attack of ocean currents. Carbonization and rehydration are the main self-healing mechanisms of cracks more minor than 200 μm. Brucite is the main self-healing product in cracks larger than 350 μm. The micromorphology observation and quantitative analysis illustrate that seawater impurities are attached to the crack surface, which may hinder the crack self-healing. [ABSTRACT FROM AUTHOR]

Abstract: Two triorganotin(IV) carboxylates [nBu3SnOL] n (KK1) and [Ph3SnOL] n (KK2) have been prepared by the reactions of (E)-3-(4-(diphenylamino)phenyl)acrylic acid (HL) with n(Bu3Sn)2O and Ph3Sn(OH), respectively. Complexes KK1 and KK2 have been structurally characterized by IR, elemental analysis and X-ray crystallography, confirming that both complexes possess infinite 1D chain structures. It’s exciting to discover that KK1 and KK2 exhibit strong solid-state luminescence emission while the HL almost quenches. Furthermore, both complexes were assayed for in vitro antibacterial activity against two Gram-positive bacterial strains (Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 6538) and two Gram-negative bacterial strains (Pseudomonas aeruginosa ATCC 13525 and Escherichia coli ATCC 35218) by MTT method. Complex KK2 exhibited powerful antibacterial activities against S. aureus with MIC value of 0.78μg/mL, which was superior to the positive controls penicillin G. On the basis of the biological results, structure–activity relationships were discussed. [ABSTRACT FROM AUTHOR]

Abstract: Three novel organotin(IV) complexes with 2-(9H-carbazol-9-yl) acetic acid (HL), of the formulae {[nBu2SnOL]2O}2 (1), [nBuSn(O)OL]6 (2) and [nBu3SnOL]6 (3) were prepared. All compounds were characterized by X-ray crystallography, confirming that complex (1) is tetranuclear one with ladder framework, complex (2) is a hexanuclear organotin(IV) complex with drum structure and complex (3) is a macrocycle with 24-membered stannoxane ring. Furthermore, all complexes were tested in vitro for their cytotoxic activity, using human hepatocellular carcinoma cell line (BEL-7402) and human hepatocellular liver carcinoma cell line (HepG2). Complex (1) displayed the best cytotoxicity and can be pointed out as a promising substrate to be subject of further investigations. [ABSTRACT FROM AUTHOR]

Abstract: Two silver(I) complexes [Ag2(dppm)2(L1)2(CH2Cl2)2] (1) and [Ag4(dppm)2(L2)2(NO3)2] (2) have been prepared by the reactions of [Ag2(dppm)2(NO3)2] with HL1 and HL2 [dppm=bis(diphenylphosphino)methane, HL1 =2-(9H-carbazol-9-yl) acetic acid and HL2 =(E)-3-(4-(9H-carbazole-9-yl) phenyl) acrylic acid], respectively. Both complexes have been structurally characterized by X-ray crystallography, confirming that 1 is a binuclear complex whereas 2 is a tetranuclear one. Both complexes were assayed for antibacterial activity against two Gram-positive bacterial strains (Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 6538) and two Gram-negative bacterial strains (Pseudomonas aeruginosa ATCC 13525 and Escherichia coli ATCC 35218) by MTT method. Complex 2 exhibited powerful antibacterial activities against B. subtilis ATCC 6633 with MIC of 0.78μg/mL, which was superior to the positive controls penicillin G. On the basis of the biological results, structure-activity relationships were discussed. [Copyright &y& Elsevier]

Two novel two-photon polymerization initiators, 10-ethyl-3-E-(4-(N,N′-di-n-butylamino)styryl)phenothiazine 5 and 10-ethyl-3,7-E,E-bis(4-(N,N′-di-n-butyl amino)styryl)phenothiazine 6, have been efficiently synthesized with room temperature solid phase Wittig reaction. Two initiators were found to exhibit good single-photon fluorescence emission and their quantum yields, lifetimes and solvent effects have been studied in detail. Two-photon fluorescence spectra were investigated under 800 nm fs laser pulse and two-photon absorption (TPA) cross-sections of the initiators have been evaluated by theoretical calculation.Two-photon initiating polymerization microfabrication experiments have been carried out and artificial defects were made and polymerization mechanism was also discussed. [Copyright &y& Elsevier]

The fabrication of high‐order multiphoton excited fluorescent materials for second near‐infrared (NIR‐II, 1000–1700 nm) light‐induced fluorescence imaging has always been an intractable challenge. In this study, a reasonable strategy guided by theoretical calculations was employed to fabricate a novel high‐order multiphoton excited fluorescence (H‐MPEF)‐responsive UiO‐type metal–organic framework (MOF, ZrTc). Strategically, the functionalization of the photonic‐responsive thiazolothiazole‐based organic ligand gave rise to amplified H‐MPEF (four‐photon activity) performance and prolonged excitation wavelength (1550 nm) of ZrTcI. The results reveal that the extended π‐electron system, enhanced charge transfer, improved dipole moment, and weakened π‐π stacking interactions within the MOFs endow them with excellent H‐MPEF performance for NIR‐II light‐induced fluorescence imaging. It is an extremely rare report on H‐MPEF bioimaging using MOFs and provide a universal strategy for the fabrication of H‐MPEF‐responsive materials. [ABSTRACT FROM AUTHOR]

The fabrication of high‐order multiphoton excited fluorescent materials for second near‐infrared (NIR‐II, 1000–1700 nm) light‐induced fluorescence imaging has always been an intractable challenge. In this study, a reasonable strategy guided by theoretical calculations was employed to fabricate a novel high‐order multiphoton excited fluorescence (H‐MPEF)‐responsive UiO‐type metal–organic framework (MOF, ZrTc). Strategically, the functionalization of the photonic‐responsive thiazolothiazole‐based organic ligand gave rise to amplified H‐MPEF (four‐photon activity) performance and prolonged excitation wavelength (1550 nm) of ZrTcI. The results reveal that the extended π‐electron system, enhanced charge transfer, improved dipole moment, and weakened π‐π stacking interactions within the MOFs endow them with excellent H‐MPEF performance for NIR‐II light‐induced fluorescence imaging. It is an extremely rare report on H‐MPEF bioimaging using MOFs and provide a universal strategy for the fabrication of H‐MPEF‐responsive materials. [ABSTRACT FROM AUTHOR]

An Ag/AgCl electrode used as a corrosion sensor in a reinforced concrete structure is considered as having good application prospect. However, its performance under complex conditions, such as dry-wet cycle condition, is not affirmed. In the current study, the performance of Ag/AgCl as chloride selective electrode in mortar exposed to dry-wet cycle condition was investigated. A simple Ag/AgCl electrode was prepared and fabricated by electrochemical anodization. These Ag/AgCl electrodes were embedded into a mortar specimen with temperature sensors, humidity sensors and anode ladder monitoring system (ALS). After 28 d curing time, the upper surface of mortar specimen was wetted (with 5% NaCl solution) and dried regularly. The obtained results indicate that Ag/AgCl electrode responds to the ingress of chloride ion, sensitively. The chloride ion concentration variation can be reflected by the potential trend. Furthermore, the balance potential of Ag/AgCl electrodes is influenced by dry-wet cycles. Compared with ALS, it demonstrates that Ag/AgCl electrodes are more sensitive to chloride. The research provides the key element for the specific application of Ag/AgCl electrode for corrosion monitoring in the future. [ABSTRACT FROM AUTHOR]

Understanding the intricate nanoscale architecture of neuronal myelin during central nervous system development is of utmost importance. However, current visualization methods heavily rely on electron microscopy or indirect fluorescent method, lacking direct and real-time imaging capabilities. Here, we introduce a breakthrough near-infrared emissive curcumin-BODIPY derivative (MyL-1) that enables direct visualization of myelin structure in brain tissues. The remarkable compatibility of MyL-1 with stimulated emission depletion nanoscopy allows for unprecedented super-resolution imaging of myelin ultrastructure. Through this innovative approach, we comprehensively characterize the nanoscale myelinogenesis in three dimensions over the course of brain development, spanning from infancy to adulthood in mouse models. Moreover, we investigate the correlation between myelin substances and Myelin Basic Protein (MBP), shedding light on the essential role of MBP in facilitating myelinogenesis during vertebral development. This novel material, MyL-1, opens up new avenues for studying and understanding the intricate process of myelinogenesis in a direct and non-invasive manner, paving the way for further advancements in the field of nanoscale neuroimaging. [ABSTRACT FROM AUTHOR]

Engineering high‐order multiphoton excited fluorescent (H‐MPEF) materials is of significant importance for sensing, 3D optical data storage and bioimaging. However, it remains a challenging endeavor due to a lack of appropriate construction strategies. This study demonstrates that incorporating octupolar modules within metal‐organic framework (MOF) offers new possibilities for the design of highly attractive H‐MPEF materials. Constructed from a typical MOF (UiO(bpdc)), the in situ formation of multibranched octupolar cyclometallated iridium(III) modules via post‐ligand coordination modification endowed the framework with enlarged static hyperpolarizabilities, an extended conjugated system, and enhanced charge transfer, ultimately unlocking its second near‐infrared (NIR‐II, 1000–1700 nm) light activated H‐MPEF performance including three‐ and four‐photon activity. Moreover, these exciting features, combined with subsequent orotic acid‐capping, enabled its application in cancer cell‐specific targeting oncotherapy using tissue‐penetrating NIR‐II light. This finding highlights the vital role of octupoles in H‐MPEF performance and sets a benchmark for unlocking the multiphoton activity of MOFs at the molecular level for deep‐seated tumor fluorescence imaging and therapy. [ABSTRACT FROM AUTHOR]

The fracture energy of the high-performance fiber-reinforced cement-based composite (HPFRCC) can be modified within wide limits by the variation of the amount of steel fibers added to the fresh mix. First of all, considering the actual engineering conditions in Qingdao, the materials commonly used in Qingdao were selected. The optimal reference mix proportion of the HPFRCC cementing material was proposed through determination of fluidity and flexural strength. Based on the optimal mix proportion, the uniaxial tensile, fracture, and dry shrinkage properties of HPFRCC with different steel fibers are systematically studied. Stress-strain diagrams of the different samples were measured under the uniaxial tensile test, wedge splitting test, and three-point bending test. The steel fiber content was varied between 0 and 200 kg/m3. The load bearing capacity and the fracture energy were determined experimentally. In addition, moisture loss as a function of time and shrinkage was determined in an environment of 20°C and 50% RH (relative humidity). The results indicate that the maximum load increases significantly in the HPFRCC series reinforced by 150 and 200 kg/m3 of steel fibers. Both have a hardening branch developed after the first crack deflection due to the high percentage of fibers bridging the crack surfaces. The load bearing capacity and fracture energy increased almost linearly with the steel fiber content. It was found that the three-point bending test is more applicable in measuring the fracture energy of HPFRCC than the wedge splitting test. The addition of steel fibers decreased the moisture diffusion and consequently the drying shrinkage of HPFRCC, and there was minimum weight loss and deformation when the steel fiber content was 150 kg/m3. The results obtained will be presented and discussed. [ABSTRACT FROM AUTHOR]

It remains challenging to control the single‐, two‐, and three‐photon excited fluorescence of metal nanoclusters. In this work, the control over the non‐linear optics of metal nanoclusters as single‐, two‐, and three‐photon excited fluorescence has been accomplished via exploiting the solvent effect. An emissive nanocluster, Au9Ag6(SPhtOMe)4(DPPOE)3Cl3, was synthesized and structurally determined. The solvent effect can not only control the fluorescence of this nanocluster, but more significantly, it can also regulate the photoluminescence nature of the cluster as single‐, two‐, and three‐photon excited fluorescence. We concluded that the increased solution polarity, improved dipole moment, enlarged HOMO–LUMO energy gap, and reduced solution viscosity of the cluster in solutions endow them with excellent high‐order multiphoton excited fluorescence. The results provide an intriguing cluster template that enables us to manipulate the linear and nonlinear optics at the atomic level. [ABSTRACT FROM AUTHOR]

It remains challenging to control the single‐, two‐, and three‐photon excited fluorescence of metal nanoclusters. In this work, the control over the non‐linear optics of metal nanoclusters as single‐, two‐, and three‐photon excited fluorescence has been accomplished via exploiting the solvent effect. An emissive nanocluster, Au9Ag6(SPhtOMe)4(DPPOE)3Cl3, was synthesized and structurally determined. The solvent effect can not only control the fluorescence of this nanocluster, but more significantly, it can also regulate the photoluminescence nature of the cluster as single‐, two‐, and three‐photon excited fluorescence. We concluded that the increased solution polarity, improved dipole moment, enlarged HOMO–LUMO energy gap, and reduced solution viscosity of the cluster in solutions endow them with excellent high‐order multiphoton excited fluorescence. The results provide an intriguing cluster template that enables us to manipulate the linear and nonlinear optics at the atomic level. [ABSTRACT FROM AUTHOR]

Spent catalysts from the hydrofining process are hazardous wastes, while their appropriate utilization can also bring enormous environmental and economic benefits. Herein, a chemical resurrection method was developed to resurrect and recycle the industrial spent NiMo/Al 2 O 3 hydrofining catalyst. The spent catalysts are calcined to remove the carbon deposit followed by the treatment with citric acid (CA) and ethylene glycol (EG). The results show that the calcination can also accelerate the aggregation and inerting of the active phase. However, the redispersion and reactivation of the inactive phases over the spent catalysts are realized through formation of metal complex with the citric acid, which weaken the interaction between Mo species and support. It increases reducibility of the Mo species and then improve the sulfurization degree of the resurrected catalyst. Besides, the average length of MoS 2 is reduced while the stacking number is increased. The ethylene glycol further regulates the reducibility of Ni and Mo species to promote the formation of NiMoS phase with high activity instead of Ni 3 S 2. Consequently, the average length of the MoS 2 is reduced while the average stacking number of MoS 2 and content of the NiMoS phase are increased over the resurrected catalyst compared with the spent catalyst. It recovers the hydrodesulfurization activity of the resurrected catalyst to a level higher than that over the spent and industrially regenerated catalyst. [Display omitted] • A chemical resurrection method is developed to resurrect the industrial spent hydrofining catalyst. • The role of citric acid and ethylene glycol in the chemical resurrection of spent catalyst was disclosed. • The hydrodesulfurization activity of the spent catalyst is recovered to a level higher than that of the regenerated catalyst. [ABSTRACT FROM AUTHOR]

Owing to the advantages of deeper penetration depth and lower biological damage, multi-photon AIE probes are widely used in the field of multi-photon therapy. We have developed a series of carbazole terpyridine manganese(II) complexes (MD1–MD3) that are promising as aggregation-induced emission (AIE) photosensitizers (PSs). MD1–MD3 exhibit excellent three-photon AIE properties in DMSO/H2O solution. We modulated the AIE properties of the Mn(II) complexes by introducing halogen atoms (Br/I). The three-photon fluorescence intensity of the complexes upon introducing halogen atoms is strong under the conditions of fw = 99% and 60%, respectively. Based on halogen-substituted carbazole ligands, MD3 can be applied as a multi-photon absorption photosensitizer which can produce 1O2 and O2˙−. MD3 damages the mitochondrial morphology, leads to a decrease in mitochondrial membrane potential, and then triggers the apoptosis of cancer cells. Furthermore, MD3 is successfully applied as a photosensitizer in tumor theranostics in vivo. This work provides a new idea for ligand modulation of multiphoton AIE ground state transition metal complexes to make them multiphoton therapeutic agents. [ABSTRACT FROM AUTHOR]

The multiphoton absorbing (MPA) materials have been extensively investigated due to their crucial merits of long wavelength excitation and short wavelength emission, of which the organometallic complexes are the most promising but still challenging candidates for developing efficient MPA materials. Herein, a novel cyclometallated iridium complex (abbreviated as SQ) is reported as a multiphoton absorption phosphorescent probe, which is constructed by coordinating the central metal Ir with diethoxyphenyl terpyridine, phenyl pyridine and SCN ligands. The single crystal of SQ exhibits a twisted octahedral structure that can avoid phosphorescence quenching caused by π-π stacking, and the push-pull electron effect of the ligand endows SQ with excellent nonlinear optical (NLO) properties under near-infrared excitation. As a result, two-photon imaging with deep tissue penetration depths is realized at the excitation wavelength of 750 nm. Meanwhile, the planar conjugated structure of diethoxyphenyl terpyridine facilitates the insertion of SQ into base pairs of mitochondrial DNA (mtDNA), thus limiting the intramolecular rotation. Consequently, the emission intensity of the SQ solution enhanced approximately 10-fold after mtDNA was introduced, which led to mtDNA-specific recognition. Our work proves a new way of designing a phosphorescence probe that can specifically identify mtDNA, thus realizing dynamic monitoring of mitochondria. • A novel cyclometallated iridium complex has been synthesized. • The complex was studied by single crystal and multi-photon emission spectra. • The mechanism of specific binding of the complex to mtDNA was revealed. • mtDNA-specific recognition and two-photon bioimaging of complex were investigated. [ABSTRACT FROM AUTHOR]

Designing new oxygenation nanomaterials by oxygen-generating or oxygen-carrying strategies in hypoxia-associated anti-tumor therapy is a high priority target yet challenge. In this work, we fabricated a nanoplatform involving Fenton-like reaction, Pd@MOF-525@HA, to relieve tumor hypoxia via oxygen-generating strategy for enhanced oxygen-dependent anti-tumor therapy. Thereinto, the porphyrinic MOF-525 can produce singlet oxygen (1O2) via light or ultrasonic irradiation for photodynamic and sonodynamic therapy. Notably, the well-dispersed Pd nanocubes within MOF-525 can convert H2O2 into O2 to mitigate the hypoxic environment for enhanced therapy outcome. Moreover, the two-photon activity and cancer cell specific targeting capability of Pd@MOF-525@HA gave rise to deeper tissue penetration and near-infrared light-induced fluorescence imaging to achieve precise guidance for cancer therapy. This work provides a feasible way in designing new oxygenation nanomaterials to relieve tumor hypoxia for enhanced cancer treatment. [ABSTRACT FROM AUTHOR]

Lipid droplets (LDs) are dynamic multifunctional organelles that participate in the regulation of many metabolic processes, visualization of which is necessary for biological research. In this work, a series of two-photon responsive fluorescent probes (C–H, C–Br, and C–I) based on carbazole units were designed and synthesized. Thereinto, an iodine-modified carbazole derivative C–I exhibited an exciting lipid droplet targeting ability due to its excellent lipophilicity. Meanwhile, benefiting from its larger Stokes shift and two-photon absorption cross-section, C–I was employed for two-photon confocal laser scanning microscopy (CLSM) and stimulated emission depletion (STED) microscopy imaging to observe LDs more accurately. In addition, given the heavy atom effect, C–I can effectively generate reactive oxygen species (ROS) leading to cancer cell apoptosis under near-infrared light irradiation. Notably, we explained the process of cell apoptosis through in vitro simulation experiments. This study provides a promising platform for visualization of lipid droplets. [ABSTRACT FROM AUTHOR]

In this study, we harness optical modulation techniques to tailor an auxiliary ligand, thereby optimizing the photophysical behavior of cyclometalated iridium (III) complexes, Ir–B and Ir-Q, for enhanced reactive oxygen species (ROS) generation. Intriguingly, the optical properties of Ir-Q's auxiliary ligands instigate a non-radiative intersystem crossover process, yielding a superior singlet oxygen (1O 2) quantum efficiency of 0.92. Further, Ir-Q's robust multi-photon absorption spectra, particularly in the Two-photon (750–800 nm) and Three-photon (1350–1600 nm) domains, open avenues for potential applications in two-photon imaging-guided photodynamic therapy targeting deep-seated tumors. This investigation underscores the pivotal role of optical structure modulation in amplifying the therapeutic potential of the iridium(III) complex, particularly in the realm of near-infrared photodynamic therapy. This work provides a promising strategy of construction design for efficient PDT by fine-tuning the auxiliary ligand structure of the iridium complex, the HOMO/LUMO overlap is tunable, thereby adjusting the ability to generate ROS. [Display omitted] • Ir-Q 's 2 PA and 3 PA cross section reaches 138.2 GM (780 nm) and 25.1 × 10−92 cm6 s2·photon−2 (1450 nm), respectively. • Ir-Q showed high ROS generation activity induced through the fine-tuning of the auxiliary ligand structure. • Ir-Q can be used in two-photon PDT based on excellent nonlinear optical properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cz-Boranil to visualise mitochondrial interaction with lipid droplets. • Cz-Boranil can demonstrated distinct intracellular distribution patterns in both normal and cancerous cells. • Cz-Boranil can successfully track the coordinated interactions of lipid droplets and mitochondria during ferroptosis and apoptosis. Intracellular lipid systems play essential roles in various physiological functions and cell growth processes. However, our understanding of the intricate interactions within this system, especially between mitochondria and lipid droplets, is limited, particularly in the context of cancer cells' altered lipid metabolism. To address this, our study introduces an N -B-O BODIPY-hexylcarbazole derivative, named Cz-Boranil, that sets a new benchmark in visualizing these critical interactions. Cz-Boranil's unique capability lies in its ability to display distinct intracellular distribution patterns in both normal and cancer cells, offering nuanced cell type-specific differentiation. More impressively, this probe tracks the coordinated interactions of lipid droplets and mitochondria during the critical processes of ferroptosis and apoptosis. We believe that the innovative capabilities of Cz-Boranil will revolutionize our understanding of intracellular lipid interactions and prove pivotal in identifying and studying cancerous cells. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is an important gas signaling molecule, is present in the alveoli in correlation with the extent of idiopathic pulmonary fibrosis (IPF) patients. In this work, a high-order multiphoton fluorescent probe FS-MnCl 2 is designed and synthesized for detecting NO level in mice model of IPF. FS-MnCl 2 has the advantage of low detection limit (11 nM) and resistance to photobleaching in vitro. The three-photon absorption cross section is greatly enhanced after FS-MnCl 2 recognizes NO. Moreover, the fluorescence intensity of FS-MnCl 2 -NO is stronger than that of FS-MnCl 2 in the presence of RNA. Biological applications suggest that FS-MnCl 2 can monitor changes in NO levels in living cells and IPF mice. This work provides a new strategy for reasonably designing Mn(Ⅱ) complex that can respond to NO for predicting IPF at an early stage. • A manganese complex with multi-photon properties for the recognition of NO. • NO has positive effect on FS-MnCl 2 recogniting RNA. • FS-MnCl 2 can be used to detect changes in NO levels in the mouse model of IPF [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal particle size effects over the bifunctional Ni/SAPO-11 hydroisomerization catalysts were investigated. • Decreasing Ni particle size significantly increases the concentration of surface Ni atoms and the proportion of low-coordinated Ni sites (corner, step sites), resulting in a significantly enhanced ability in adsorption and activation of the reactants. • The higher intrinsic catalytic activity of smaller Ni particle for n-hexane hydroisomerization is due to the higher proportion of low-coordinated Ni sites. • The smaller Ni particle enhance the metal–acid synergy and prevent the intermediate from undergoing excessive acid-catalyzed steps, leading to a higher selectivity to isomers. The prominent size effects of metal nanoparticles (NPs) are mainly reflected in the change of electronic and geometric properties, which may induce distinct catalytic performance of the catalyst. Herein, Ni/SAPO-11 bifunctional catalysts with controllable sizes of Ni NPs were synthesized to investigate the particle size effects in n-hexane hydroisomerization. The results show that decreasing Ni particle size from 11.7 to 5.3 nm increases the concentration of surface Ni atoms and the proportion of low-coordinated Ni sites (corner, step sites) by 1.7 and 1.5 times, respectively. The low-coordinated surface Ni atoms have rich dangling bonds and high surface energy, resulting in greatly improved H 2 adsorption and activation abilities. Moreover, an increased proportion of low-coordinated Ni sites within the Ni cluster shifts the d-band center upward, further enhancing the adsorption and activation of reactants. The intrinsic catalytic activity (turnover frequency) of 5.3 nm Ni NPs is ca. 2 times as much as that of the 11.7 nm ones. Besides, the smaller Ni NPs enhanced the metal–acid synergy, leading to a higher selectivity to isomers. This work provides deep insights into the metal particle size effects over the bifunctional Ni/SAPO-11 hydroisomerization catalysts and can be extended to various metal supported catalysts. [ABSTRACT FROM AUTHOR]

Compared to general fluorescent probes, multi-photon fluorescent probes exhibit deeper tissue penetration, lower auto-fluorescence and lower photo-toxicity in the bio-imaging field. Herein, we synthesized a series multi-photon fluorescent probe (L1–L3) based on quinolone groups. Of notably, the three-photon fluorescence of L3 significantly enhanced when L3 interacted with liposome; moreover, L3 exhibited high selectivity towards lipid droplets in living cells. Due to its large Stokes shift, high selectivity and photon-stability, L3 was successfully used in lipid droplet imaging via multi-photon fluorescence bio-imaging. [ABSTRACT FROM AUTHOR]

Organic mechanofluorochromic (MFC) materials with mechanical‐induced emission enhancement (MIEE) are scarce. Herein, Aggregation‐induced emission (AIE)‐active tetraphenylethene‐functionalised pyrazoline derivatives with various non‐conjugated substituent groups (Br, F, N,N‐dimethylamino and cyano groups for TPEB, TPEF, TPEN and TPECN, respectively) were designed and synthesised. The fluorescence spectra of the compounds in the solid state were sensitive to mechanical stimuli and exhibited unique MFC properties. The solid fluorescence peaks of all compounds were red shifted, whereas the quantum yields of TPEB, TPEF and TPEN were increased and that of TPECN was slightly reduced after grinding. The MIEE mechanism was systematically investigated through structure–property relationship studies. The results showed that the pyrazoline ring of TPEB with MIEE property formed H‐dimer aggregates with weak π–π stacking in the solid state. After grinding, the synergistic effects of conformational planarization and destructive π–π interactions induced the red shift of the fluorescence peak and the intensity enhanced. TPECN formed incompact J‐aggregates with weak intermolecular interactions instead. The conformational planarization and increased intermolecular interactions induced by grinding led to the red‐shifted peak and the slightly reduced intensity. These results clearly demonstrated that the translation of packing arrangements is an efficient method to design MIEE materials, which opens a new scope for designing unique MFC materials. [ABSTRACT FROM AUTHOR]

We present the design and synthesis of water-soluble quinoline–indole-based derivatives (IM-1, IM-2, and IM-3) with three-photon absorption activity. IM-3 can specifically target DNA and RNA accompanied by an obvious three-photon fluorescence enhancement in the second near-infrared window (1000–1700 nm). The in vitro experiments demonstrate that IM-3 can simultaneously stain mitochondria and the nucleolus both in living and fixed cells. The organelle-specific targeting behaviour is successfully visualized under stimulated emission depletion (STED) nanoscopy. [ABSTRACT FROM AUTHOR]

As a cardinal membrane-bound organelle, endoplasmic reticulum (ER) plays a critical role in maintaining cellular and organismic metabolic homeostasis. Accurately detecting the dynamic changes of ER is essential for understanding their biological functions and pathological roles. Here, a novel water-soluble terpyridyl-based derivative L with aggregation-induced emission (AIE) property was synthesized, which can be used as a fluorescent probe to track ER in cells for its good photostability, membrane permeability and biocompatibility. The selective experiments, molecular modeling calculations and 1H NMR titration showed that positively charged characteristic and amphiphilic properties of L were the main reason of enhanced emission for probe L in ER. Probe L bound with cells through electrostatic interactions, and then the hydrophobic group embedded into phospholipid contents in ER membranes, which allowed its fluorescence emission based on the progress of restriction of intramolecular motion. Image 1 • The novel AIE probe based on the luminous mechanism of restrict intramolecular motion target the endoplasmic reticulum. • Probe L can be used as high-efficient fluorescent probe to track ER in living cells. • The hydrophobic group of L embedded into the hydrophobic region of lipid bilayer, and restrict intramolecular motion of L was the main reason for probe to track ER. [ABSTRACT FROM AUTHOR]

Two novel carbazole derivatives containing tetraphenylethylene and cyano groups have been synthesized and characterized. The only difference between TPECZ and TPECZBr is at the C-8 and C-1 positions with or without a Br atom. Interestingly, they exhibited similar photophysical properties in solution, while their quantum yields and molecular packing models in solid state were significantly different. It was confirmed by single crystal structure analysis that the presence of a Br atom changed the molecular packing. Meanwhile, the two compounds exhibit mechanochromism (MC) behaviors, that the fluorescence emissions can be changed between yellow and orange. The powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) suggested that the MC mechanism of TPECZ and TPECZBr can be correlated with a phase transition between crystalline and amorphous states. Two novel carbazole derivatives containing tetraphenylethylene and cyano groups exhibited obviously aggregation-induced emission (AIE) characteristics, different quantum yields in the solid state and reversible mechanochromic (MC) properties. Image 1 [ABSTRACT FROM AUTHOR]

Micronucleus (MN) is regarded as an abnormal structure in eukaryotic cells which can be used as a biomarker for genetic instability. However, direct observation of MN in living cells is rarely achieved due to the lack of probes that are capable of distinguishing nuclear- and MN-DNA. Herein, a water-soluble terpyridine organic small molecule (ABT) was designed and employed to recognize Zinc-finger protein (ZF) for imaging intracellular MN. The in vitro experiments suggested ABT has a high affinity towards ZF. Further live cell staining showed that ABT could selectively target MN in HeLa and NSC34 cells when combined with ZF. Importantly, we use ABT to uncover the correlation between neurotoxic amyloid β-protein (Aβ) and MN during Alzheimer's disease (AD) progression. Thus, this study provides profound insight into the relationship between Aβ and genomic disorders, offering a deeper understanding for the diagnosis and treatment of AD. [ABSTRACT FROM AUTHOR]

Visualization of 1O 2 in cells is of great significance for revealing the laws of life activities. Although many 1O 2 fluorescent probes have been reported, their mechanism of capturing 1O 2 has not been innovated. Herein, we report a ruthenium(Ⅱ) bipyridyl complex [Ru(bpy) 2 L 3 ]PF 6 with the ability to specifically identify 1O 2 based on a novel mechanism of action. The non-fluorescent [Ru(bpy) 2 L 3 ]PF 6 can be accurately oxidized by 1O 2 to generate a fluorescent substance with a large Stokes shift (184 nm). [Ru(bpy) 2 L 3 ]PF 6 was successfully applied for visualizing the generation process of 1O 2 in living cells and monitoring the morphological changes of mitochondria during photodamage. Therefore, [Ru(bpy) 2 L 3 ]PF 6 has potential to be a useful molecular probe for analyzing physiological processes related to 1O 2 in organisms. • [Ru(bpy) 2 L 3 ]PF 6 achieves 1O 2 capture and sensing in a new way. • [Ru(bpy) 2 L 3 ]PF 6 is able to target mitochondria and shows high specificity for 1O 2. • [Ru(bpy) 2 L 3 ]PF 6 can visualize the generation process of 1O 2 in living cells. [ABSTRACT FROM AUTHOR]

Live cell actin visualization is fundamental for exploring cellular motility, cytokinesis, intracellular transport, and other correlated functions. The current imaging techniques that allow imaging of actin in its native environment are optical and electron microscopy. Such imaging techniques offer high enough resolution to investigate the ultrastructure of actin however they come at the expense of actin integrity. Inspired by the lack of suitable probes that preserve actin's integrity, we designed a cyclometalated Ir (III) complex that interacts with live cells and displays light switch behaviour upon specific actin binding. The exceptional photophysical properties of the proposed probe allow unprecedented resolution of cytoskeleton ultrastructures under stimulated emission depletion (STED) super-resolution nanoscopy. Moreover, the Ir complex enables the capability of visualizing actin polymers and periodicity under correlative light electron microscopy (CLEM) and liquid-phase electron microscopy (LPEM) at ∼ 8 nm resolution. • Ir-DE complex suitable for STED imaging of live cells actin structure. • Ir-DE allowing observation of actin under correlation light and electron microscopy. • Ir-DE could observed actin nano-structure under Liquid phase electron microscopy. [ABSTRACT FROM AUTHOR]

Abstract Developing small-molecular fluorescent sensors for the detection of pH fluctuation is highly demanded yet challenging. Herein, a novel pH sensor, stilbazolium-based compound L1 , was rational designed and developed. Notably, the two-photon activity responds strongly to protonation due to the increased extent of symmetrical charge transfer within molecule. Benefiting from the considerable two-photon activity and biocompatibility, it was observed that L1 could certainly sensor pH changes in living cells by using two-photon confocal microscopy and stimulated emission depletion nanoscopy methods. Highlights • L1 possess excellent water solubility and biocompatibility. • L1 responds strongly to pH fluctuation. • pH sensing mechanism was proposed by 1H NMR titration and mass spectra. • L1 can specific target to mitochondria and monitor pH changes in living cells. • L1 was successfully applied to tumor targeted imaging. [ABSTRACT FROM AUTHOR]

Abstract Small molecules emitting in the NIR for tracking mitochondrial pH alteration with super-resolution are expected to play an essential role in biomedical applications. Herein, two small molecules based on pyridinium salt (P1 and P2) have been synthesized and systematically investigated. It was found that pyridinium salts P1 and P2 emitted in the NIR (about 610 nm), which could detect pH changes from 2.0 to 11.0 with good linearity and high sensitivity. Importantly, P2 could precisely target cellular mitochondria in a real-time manner under stimulated emission depletion (STED). These results implied a chemical strategy with a potential application in super-resolution imaging and mitochondrial pH determination. Graphic abstract fx1 Highlights • Synthesis and investigation of small molecules based on pyridinium salt (P1 and P2). • Detection of pH changes from 2.0 to 11.0 with a good linearity and high sensitivity. • Uniform distribution of P2 within the cytosolic region and excluded from the nucleus. • Localization of P2 into mitochondria and sensitivity to mitochondrial environment. • Monitoring mitochondrial pH variation in a real-time under stimulated emission depletion (STED). [ABSTRACT FROM AUTHOR]

Multi‐stimuli responsive D‐π‐A molecular (named CZIZ) comprising of carbazole as D, dicyano as A and imidazole as functional group was designed and synthesized. The photophysical properties showed that CZIZ possessed the property of aggregation‐induced emission enhancement (AIEE) property, which was verified by UV‐vis absorption and fluorescence spectra. In addition, the large twisted structure and loose arrangement induced CZIZ performed high color contrast mechanochromic (MC) behaviors from 537 nm to 584 nm, which was successfully applied in ink‐free rewritable paper. Furthermore, CZIZ showed high selective detection for picric acid (PA) in aqueous medium due to the excellent proton‐binding property of the imidazole group, which was verified by1H NMR spectra. The density functional theory verified that the fluorescent quenching mechanism is a photoinduced electron transfer (PET) process between CZIZ and PA. The compound CZIZ described herein will efficiently expand the development of design principles to supply diverse multifunctional tools for material science and material engineering. [ABSTRACT FROM AUTHOR]

Abstract A series of compounds (W1 - W8) based on triphenylamine with -C=N- or -NH- group, were designed and studied by fluorescence emission spectra and DFT/TDDFT calculations. Probes W1 - W4 were selectively leveraged to sensitively detect glutathione by two distinct reaction mechanisms, thereinto, W1 - W2 featured a convenient detection for glutathione using hydrolysis and W3 - W4 utilized displacement to probe glutathione possessing sensitivity and practicability. Compound W5 - W8 here provided an avenue for understanding structure-property relationship. Taken considerations for toxicity and biocompatibility together, W1 - W4 showed great advance for endogenously and exogenously imaging GSH in living cells. Graphical abstract Image 1 Highlights • A series of fluorescent probes for monitoring glutathione were synthesized. • Structural relation adjustment introduced two distinct reaction mechanisms: hydrolysis and replacement. • The probes had a good advantage for further endogenously and exogenously monitoring glutathione in vivo. [ABSTRACT FROM AUTHOR]

Abstract Detection of nitroaromatic explosives especially picric acid (PA) is considerably worth concern on human safety and homeland security. Herein, we developed an effective probe (APPTPEP) for PA detection in aqueous medium by combination of 1,4-dihydropyrrolo[3,2- b ]pyrrole with tetraphenylethylene and pyridine units. The incorporation of tetraphenylethylene unit in the backbone endows the APPTPEP a significant aggregation induced emission (AIE) behavior. Pyridyl group was proved as recognition site for PA and their strong interaction was confirmed by 1H NMR titration and supported by theoretical calculation. Owing to this strong affinity, APPTPEP exhibited high selectivity and sensitivity (limit of detection 31.5 nM) to PA over other nitroaromatic compounds. This research provides new insights into the rational design of AIE-active materials for effective sensing application. Graphical abstract Image 1 A novel 1,4-dihydropyrrolo[3,2- b ]pyrrole derivative containing tetraphenylthylene and pyridyl group exhibiting aggregation-induced emission and achieving highly sensitive and selective detection of picric acid in water at acidic condition. Highlights • A novel 1,4-dihydropyrrolo[3,2- b ]pyrrole derivative shows obviously aggregation-induced emission (AIE) characteristic. • APPTPEP showed a highly selective and sensitive for picric acid (PA) in water sample. • The detect limit of PA as low as 31.5 nM. [ABSTRACT FROM AUTHOR]

Abstract Pyrophosphate (PPi) played crucial roles in various fundamental physiological processes. Herein, a two-photon absorption (TPA) "On-Off-On" type benzoxazole-based fluorescence probe BN was designed and synthesized, which detected PPi through Cu2+ displacing method in situ system in aqueous medium. The on-off-on process of BN recognizing PPi was verified by mass spectra and theoretical calculations, which was successfully applied in TPA cells imaging. Graphical abstract fx1 Highlights • Compound BN detected PPi through Cu2+ displacing method in situ system. • Compound BN recognizing pyrophosphate showed good two-photon absorption properties in aqueous solution of DMSO (1:1, v/v). • The cycle process of compound BN was applied in live cell imaging, which highlighted their practical performance. [ABSTRACT FROM AUTHOR]

Abstract Compared to organotin (IV) compounds with biochemical activity, two-photon absorption (2PA) organotin (IV) complexes for targeting nuclear with anticancer activities are rarely reported. Here, two novel 2PA organotin (IV) cyano carboxylate complexes (C1Sn - 1 , C1Sn - 2) are synthesized and characterized. The two-photon absorption cross section values (δ) in the near-infrared region are significantly enhanced for C1Sn - 2 compared to C1Sn - 1 , thus developing for targeting nuclear by two-photon fluorescence microscopy (2PFM). C1Sn - 2 could specifically target nuclear DNA in vitro. The mechanism demonstrated that there are abundant hydrogen bond interactions between hydroxy group of C1Sn - 2 and DNA. The animal mode studies are first proposed that C1Sn - 2 displayed a certain anti-cancer efficiency with non-significant toxicity. Graphical abstract Unlabelled Image Highlights • The 2PA organotin (IV) complex C 1 Sn 2 are developing for targeting nucleus. • C 1 Sn 2 could specifically recognize nucleus DNA in vitro. • The animal model studies showed that C 1 Sn 2 displayed a certain anti-cancer efficiency. [ABSTRACT FROM AUTHOR]

In this study, by employing mixed organic ligands through rational design and metal ions as the initial reactants, a series of novel metal–organic frameworks (AHU-TW1 to 6) were synthesized by a solvothermal method. Herein, accessible Lewis base sites originating from organic ligands within MOFs act as functional sites that can interact with the analyte possessing protons and then lead to obvious variations in the fluorescence spectra. Due to their superiority, AHU-TW1, 3, 4 and 6 are able to recognize trinitrophenol (TNP) with high sensitivity and a low detection limit. [ABSTRACT FROM AUTHOR]

Herein, a series of photosensitizers were constructed of α, β and γ-isomers of terpyridine and the corresponding N-methylation derivatives. Benefiting from the tunable singlet–triplet energy gap and aggregation-induced emission characteristics, two-photon active photosensitizers L2b and L2c showed relatively strong intersystem crossing facilitating 1O2 generation and cell apoptosis with near-infrared excitation. [ABSTRACT FROM AUTHOR]

A novel symmetrical indolo[3,2- b ]carbazole derivative ( ICZ-CN ) containing dicyanovinyl groups has been designed and synthesized. The typical D-π-A type conjugated compound exhibited an obvious intramolecular charge transfer (ICT) property, which was evidenced by UV-vis absorption, fluorescent emission spectroscopy and density functional theory (DFT) calculations. Meanwhile, ICZ-CN exhibited a strong aggregation-enhanced emission (AEE) characteristic. Interestingly, compound ICZ-CN showed a reversible mechanofluorochromic (MFC) property between yellow and orange-red emission by grinding-fuming processes. The MFC mechanism was investigated through the single crystal structure, the scanning electron microscope (SEM) and the powder X-ray diffraction (XRD). The results showed that the mechanofluorochromic property is attributed to the loose molecular packing by weak intermolecular hydrogen bond interactions was destroyed and generated the phase transformation from crystalline to amorphous states under external stimulations. The results would be of great help in understanding and designing new MFC materials. [ABSTRACT FROM AUTHOR]

Materials with aggregation-induced emission (AIE) and their applications have still been hot spot in material science. At present work, three novel D–A type phenanthridine derivatives ( Sa, Sb and Sc ) had been synthesized and fully characterized. The relationships between the structures and photophysical properties of the three compounds were investigated with aid of experimental and theoretical calculation methods. The results shows there are only ICT and π-π* transitions in the three compounds. Additionally, the three compounds showed excellent aggregation-induced one- and two-photon emission enhancement (AIEE) properties. To better understand the AIEE properties, dynamic light scattering (DLS) and scanning electron microscopy (SEM) were performed, explaining that the small and uniform particles are beneficial to improve fluorescence emissions. Furthermore, the enhanced aggregation-induced emission was deeply understood based on crystal structural information. Except, third-order nonlinear optical properties also were systematically determined by open/close aperture Z-scan methods using tunable femtosecond laser. The results revealed that Sb possesses largest two-photo absorption (2PA) coefficient ( β  = 0.349 cm/GW) and cross sections ( σ  = 1669.306 GM) compared to the others. Lastly, the three compounds also can be applied in cell imaging because of their good biocompatibility and lower cytotoxicity. [ABSTRACT FROM AUTHOR]

A novel multifunctional probe, L , based on triphenylamine o -hydroxyl Schiff base was constructed for the sequential detection of Zn 2+ /P 2 O 7 4− . Interestingly, probe L also showed two-photon fluorescent “off-on” response to Zn 2+ along with a large effective two-photon absorption cross-section value of 240 GM at 720 nm, a low cytotoxic and a moderate photostability, which made L a good candidate for two-photon fluorescence microscopy imaging and monitoring the fluctuation of exogenous Zn 2+ . [ABSTRACT FROM AUTHOR]

Herein, a series of multifunctional oxethyl triphenylamine substitutional terpyridyl analogues ( 1 , 2 , 3 , 4 and 5 ) with aggregation-induced emission (AIE), two-photon absorption (2PA) and specially targeted mitochondria were presented. Their photophysical properties were systematically explored by two-photon excited fluorescence measurements and theoretical calculations. Importantly, the AIE mechanism was explained relying on their crystal structural information. It indicated that the introducing of oxethyl and π bridge of phenyl caused the fluorescence quenching in organic solvent and AIE in mixed solvent of ethanol and water. The nonlinear optical test revealed that strong ICT with a large dipole moment and high asymmetry of the terpyridyl analogue molecules were benefited for 2PA. Finally, based on their photophysical properties, the biological imaging applications were carried out, which indicated that the terpyridyl analogues may be potential biological probe for targeting mitochondria. [ABSTRACT FROM AUTHOR]

Two novel organo tin carboxylate complexes (BuSnO) 6 L 6 and Bu 3 SnOL , where L  = a cinnamic acid unit containing polyether chains, were rationally designed for two-photon fluorescent imaging and anticancer purpose. The organotin (IV) complex (BuSnO) 6 L 6 possessed strong one-photon exited fluorescence (1PF) intensity and moderate two-photon absorption cross-section in the near infrared region. Living cell evaluation revealed that (BuSnO) 6 L 6 exhibited good bio-compatibility and outstanding selectivity in the selected tumor cell lines as well as in the normal cells. Furthermore, the anti-tumor activity and mechanism of (BuSnO) 6 L 6 have been investigated systematically. The results indicated that (BuSnO) 6 L 6 could induce apoptotic cell death through a mitochondrial dysfunction, ROS (Reactive oxygen species produced by cell during metabolism) and Cytochrome c elevation pathway. This work provides a novel strategy for rationally designing carboxylate organotin complex with two-photon activity and anti-tumor activity. [ABSTRACT FROM AUTHOR]

Two novel similar structural coumarin-based fluorescent compounds L1 and L2 employing ether oxygen chain and 2 – pyridine unit had been prepared to explore the effect of structural adjustment on property. The prepared L2 through slightly adjusting structure of L1 exhibited the prominent fluorescence responses to Hg 2+ and Cu 2+ in H 2 O, which could monitor the corresponding metals ion in mitochondria of Hela cells, but L1 only recognized Hg 2+ through turn-on fluorescence response in CH 3 OH/H 2 O, fluorescence co-localization studies illustrated that the L1 mainly located at lysosome. The recognition mechanism had been established by 1 H NMR titration, Job’s plot, MAlDI-TOF mass spectrometry and single crystal structure. Bio-imaging experiments revealed that L1 and L2 could qualitatively monitor Hg 2+ or Cu 2+ in Hela cells and mouse kidney tissues. [ABSTRACT FROM AUTHOR]