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A salamo-salen-salamo hybrid fluorescent chemical sensor (H 4 L) was synthesized and characterized. It exhibits high selectivity and sensitivity to Zn2+ in physiological pH range. Meanwhile, its Zn(II) complex (L-Zn2+) continuously responses phosphate anions in DMF/H 2 O (v/v, 9:1) solution. The sensing mechanisms of H 4 L and L-Zn2+ towards Zn2+ and phosphate anions were investigated by ESI-mass spectrometry, FT-IR spectra and Spectroscopic analyses to further understand experimental consideration results observed. [Display omitted] • H 4 L is a novel salamo-salen-salamo hybrid compound. • H 4 L is a Relay-Sensor for high sensitive and selective detection of Zn2+/phosphate anions. • A detection strategy based on fluorescence enhancement effect on Zn2+ and continuous fluorescence quenching on phosphate ions was developed. • Both of the H 4 L and L-Zn2+ chemosensors have a certain practical application value and advantage. A salamo-salen-salamo hybrid fluorescent chemical sensor (H 4 L) was synthesized and characterized. It exhibits high selectivity and sensitivity to Zn2+ in physiological pH range. Meanwhile, its zinc(II) complex (L-Zn2+) continuously responses phosphate anions in DMF/H 2 O (v/v, 9:1) solution. Moreover, the identification processes are explored using characterization methods such as UV-absorption spectra, IR spectra and ESI-MS spectrum. In addition, the coordination mechanism of H 2 PO 4 − and Zn2+ were successfully exploited to make the chemical sensor reproducible. In short, the sensors H 4 L and L-Zn2+ will be promising detection devices for Zn2+ and phosphate anions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel symmetrically double-armed salamo type fluorescent sensor BMS was synthesized. • The high sensitivity and selectivity of BMS in the recognition of MnO 4 - were investigated. • The limit of detection (LOD), limit of quantification (LOQ), and the binding constant (K a) were calculated. • The recognition mechanism of MnO 4 - by BMS has been postulated. • The energy gaps before and after recognition were analyzed by DFT calculation. The symmetrically double-armed salamo type fluorescent sensor BMS , incorporating benzimidazole units, was designed and synthesized. Showcasing remarkable specificity and responsiveness to MnO 4 - within a DMSO:H 2 O (V/V = 9:1, pH = 7.2) Tris-HCl buffer medium, it enabled dual-channel detection of MnO 4 - through fluorescent and colorimetric changes. Critical experimental parameters, including detection and quantification thresholds (LOD and LOQ) along with binding affinity constants (K a), were calculated using the Origin software. A rational interaction mechanism between BMS and MnO 4 - was deduced, based on fluorescence titration, Electrospray Ionization Mass Spectrometry (ESI-MS), Ultraviolet–Visible Spectroscopy (UV–Vis), Infrared Spectroscopy (IR), Stern-Volmer plots, and Density Functional Theory (DFT) computations. Additionally, the sensor BMS was applied to monitor MnO 4 - in real water samples. Advancing its practical utility, BMS was fabricated into test strips for the selective detecting of MnO 4 -. [ABSTRACT FROM AUTHOR]

[Display omitted] • The probe H 3 L was synthesized with a simple and easily accessible preparation. • H 3 L identifies B 4 O 7 2- by dual fluorescence and colorimetric channels. • The identification possesses high selectivity, fast response and low detection limit. • Good results were obtained in both bean sprout imaging and actual water sample testing. A bis(salamo)-like chemical sensor H 3 L ((1 E ,3 E)-2-hydroxy-5-methylisophthalaldehyde O , O -di(3-((((E)-(2-hydroxynaphthalen-1-yl)methylene)amino)oxy)propyl) dioxime) was constructed. H 3 L is capable of recognizing B 4 O 7 2- in H 2 O/DMF (1:9, v/v) solution by both fluorescent and colorimetric channels, bright green fluorescence was turned on when B 4 O 7 2- was added to H 3 L and changed from colorless to yellow in natural light. The detection limit was 3.21 × 10−8 M. The identification has good anti-interfering ability, quickly responsive time (5 S) and broad pH detecting range (pH = 5–12). The mechanism of action was determined by 1H NMR titration, infrared spectrometry, HRMS spectra and further elucidated by theory calculations. The fluorescence imaging of bean sprouts and spiked recovery assays of actual water samples demonstrated the practical use of sensor H 3 L for the detection of B 4 O 7 2−, which is expected to have applications for the detection of B 4 O 7 2− in plants and the environment. [ABSTRACT FROM AUTHOR]

A new salamo-like fluorescent chemosensor H 2 L was synthesized, which can selectively recognize Cu2+ and B 4 O 7 2− ions. The sensing mechanism of the sensor was studied through the relevant experiments. The H 2 L sensor's good biocompatibility and excellent water solubility make it very advantageous in practical applications, the sensor H 2 L powder can be used for fingerprint visualization, it can also be loaded on portable test paper for ion detection, and the mixture of the sensor H 2 L and B 4 O 7 2− ions can be used as ink to print safety information. [Display omitted] • A salamo-like fluorescence sensor H 2 L was designed and synthesized. • The sensor H 2 L can selectively recognize Cu2+ and B 4 O 7 2−. • The sensor H 2 L powder can be used for fingerprint visualization. • The mixture of H 2 L and B 4 O 7 2− ions can be used as ink to print safety information. • H 2 L can be loaded on a portable test strip for actual testing of Cu2+ and B 4 O 7 2−. An innovative salamo-like fluorescent chemical sensor H 2 L , has been prepared that can be utilized to selectively detect Cu2+ and B 4 O 7 2− ions. Cu2+ ions can bind to oxime state nitrogen and phenol state oxygen atoms in the chemosensor H 2 L , triggering the LMCT effect leading to fluorescence enhancement. The crystal structure of the copper(II) complex, named as [Cu(L)], has been achieved via X-ray crystallography, and the sensing mechanism has been confirmed by further theoretical calculations with DFT. Besides, the sensor H 2 L recognizes B 4 O 7 2− ions causing an ICT effect resulting in bright blue fluorescence. Moreover, the sensor has relatively high selectivity and sensitivity for Cu2+ and B 4 O 7 2− ions, and the detection limits are 1.02 × 10−7 and 2.06 × 10−7 M, respectively. In addition, the good biocompatibility and excellent water solubility of the sensor H 2 L make it very advantageous in practical applications, using H 2 L powder for fingerprint visualization, using H 2 L to identify the phenomenon of B 4 O 7 2− ions emitting bright blue fluorescence, making it an ink that can print encrypted messages on A4 paper, in addition to this, based on H 2 L , the real water sample was tested for Cu2+ ion recognition, and finally the test strip experiment was carried out. [ABSTRACT FROM AUTHOR]

[Display omitted] • The nitrogen heterocycles improve the application value of salamo compounds. • It is rare that the probe can recognize anions stably in a solution with high water content. • The probe achieves the purpose of recognition by oxidative hydrolysis of C = N bond. A unique fluorescent probe Ni-DAS was developed by a nitrogenous heterocyclic oligo(N,O-donor) salamo-based compound DAS. DAS exhibits AIE and ESIPT effects which are extremely infrequent in salamo-based multi-oxime compounds. In addition, Ni-DAS can be used as a fluorescent probe with high selectivity and sensitivity to recognize Cr 2 O 7 2- in DMF with 80 % water content, which enhances the value of the probe for application in real environments, and outperforms most similar molecular fluorescence probes. The probe Ni-DAS can recognize Cr 2 O 7 2- by oxidative hydrolysis of C = N bonds, which promotes further research on theory of C = N bond hydrolysis, and the binding ratio and recognition mechanism were verified and supported by relevant theoretical calculations (DFT & MESP). The experiments showed that the probe Ni-DAS can be used for ion detection in real environments. It provides a new strategy for the oxidative hydrolysis of C = N bond and the structure of salamo-based compounds with AIE nature, and offers new ideas for study ion recognition and acidity detection. [ABSTRACT FROM AUTHOR]

A novel bis(salamo)-like probe FT was successfully determined, it prescented fluorescent decreased phenomenon for Fe3+ and Cu2+ ions and colorimetric sensing ability towards Cu2+ ions, and excellent applicability were constructed in test filter paper to highly sensitive monitoring Fe3+ and Cu2+ ions. [Display omitted] • A novel and effective bis(salamo)-like probe FT was first successfully developed. • FT uses as a fluorescent ON-OFF probe for Fe3+ and Cu2+ ions. • Theoretical calculations were further applied to explore electronic properties. • FT was employed for monitoring Fe3+ and Cu2+ via test filter paper in real time. A novel bis(salamo)-type sensor FT for fluorescence-colorimetric recognition of Fe3+/Cu2+ has been created, which revealed significant fluorescent performance and colorimetric sensing ability for Cu2+ and Fe3+ ions, superior to other related competitive metal ions. Interestingly, the binding of the FT probe with Cu2+ ions manifested an instant color change from colorless to red in sunlight, which is detectable by the naked-eye, and a fluorescence turn-off response under UV light for Fe3+ and Cu2+. The results demonstrated that the probe exhibits better sensitivity, greater affinity and lower limit of detection leading to quick response time in an aquo-organic medium. The excited state property of the FT probe and in the presence of Cu2+/Fe3+ was evaluated on the basis of DFT & TD-DFT results. Furthermore, test strips have been provided for convenient monitoring of Cu2+ and Fe3+ ions by naked eye and fluorescence method. [ABSTRACT FROM AUTHOR]

Designed and synthesized a bis(salamo)-like fluorescent chemical sensor BS , which can be used as a highly selective and sensitive fluorescent probe for HCO 3 – and CO 3 2– detection. The sensing mechanism was investigated and the application of the sensor in practice was explored. In the field of ion detection, salamo-like chemical sensors have been less studied compared to other sensor molecules, especially for the recognition and detection of anions. Therefore, this study will to some extent contribute to expanding the application of salamo-like compounds. [Display omitted] • A bis(salamo)-like fluorescent sensor BS was designed and synthesized. • Sensor BS enables selective identification of HCO 3 – and CO 3 2– based on "turn-on" fluorescence. • Sensor BS is capable of being loaded on portable test strips for the practical testing of HCO 3 – and CO 3 2–. In this work, we successfully designed and synthesized a methoxydisubstituted bis(salamo)-type fluorescent chemical sensor BS , which can be applied as a highly sensitive and selective fluorescence probe for HCO 3 – and CO 3 2– detection. The LODs of HCO 3 – and CO 3 2– were experimentally calculated to be 5.4068 × 10−8 M and 4.4517 × 10−8 M, respectively. After relevant experiments, the sensing mechanism was investigated. Moreover, the application of the sensor in practice is explored, and the sensor BS can be loaded on portable test strips for ion detection. In the field of ion detection, salamo-like chemical sensors have been less studied compared to other sensor molecules, especially for the recognition and detection of anions. Therefore, this study will to some extent contribute to expanding the application of salamo-like compounds. [ABSTRACT FROM AUTHOR]

A novel Salamo-Salen-Salamo-Zn(II) complex fluorescent sensor ZT was successfully synthesized, and exhibited fluorescent quenching effect and excellent applicability through solid-state fluorescent strips and biological imaging experiments on zebrafish and bean sprout to highly sensitive monitoring H 2 PO 4 - ions. [Display omitted] • A novel and effective Salamo-Salen-Salamo-Zn fluorescent sensor ZT was successfully developed. • It is worth noting that ZT serves as a fluorescence ON-OFF sensor by adding H 2 PO 4 - in the presence of excess other anions. • The sensor ZT was successfully studied using the solid-state fluorescence of the test strips. • Bioimaging experiments were conducted on zebrafish and bean sprouts using a confocal microscope. A newly designed and synthesized Salamo-Salen-Salamo-Zn(II) complex sensor (sensor ZT) was extensively explored for anion sensing studies. The selectivity and sensitivity of the sensor ZT towards H 2 PO 4 - ions were based on ICT and CHEF effects, and via displacement pathways in DMSO/H 2 O (9:1, v/v) medium in the presence of other anions like, PO 4 3-, HPO 4 2- and P 2 O 7 4- in a short time, separately. The prepared ZT sensor has excellent association constant and low detection lines. The sensing mechanism and binding mode of the sensor were studied by UV–Vis spectroscopy, HR-MS, 1H NMR titration and theory calculations (DFT & TD-DFT) for analytes. The time response and stability of the sensor are also given. Meanwhile, the sensor ZT can be widely used as a simple and effective solid-state optical sensor to detect H 2 PO 4 - by intuitive fluorescence changes. In addition, besides the environment can be used as a powerful instrument for detecting H 2 PO 4 -, based on the good biocompatibility and tissue permeability of ZT , effectively monitoring H 2 PO 4 - in cellular distribution by confocal microscopy using Zebrafish and bean sprout. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon dots with aggregation induced fluorescence were synthesized using a one-step solvothermal method. • The prepared carbon dots exhibit different fluorescence colors in different solvents. • The carbon dots were used to make an anti-counterfeiting luminous ink, which can be used for encryption in reversible double switch mode. Aggregation-induced emission luminogens (AIEgens) have garnered significant attention because of their outstanding photophysical characteristics. AIEgens are used in fluorescence imaging, sensors, tumor treatment, and other related fields. However, the synthese of these AIEgens are relatively complicated and requires expensive raw materials. These drawbacks limit their applications and development to a certain extent. In this study, using cheap and convenient materials, we developed a new type of carbon dots (O-CDs) using a one-step solvothermal method, which has the potential to become a new AIEgen. O-CDs exhibit different fluorescence colors in different solvents, and they exist as monomers in ethylic acid and, ethanol alcohol, etc., exhibiting blue fluorescence. After adding water, the fluorescence of O-CDs gradually turns orange red, because the internal rotation of the disulfide bond molecules is restricted and the AIE effect occurs. Using the unique AIE performance of O-CDs, we fabricated an anti-counterfeiting luminous ink, that can be used for encryption in the reversible double switch mode. [ABSTRACT FROM AUTHOR]

A novel bifunctional-group multi-purpose dye probe p-TNS, with a unique excited-state intramolecular proton transfer (ESIPT) and resonance-assisted hydrogen bonding (RAHB) coupled system, was confirmed to detect cyanide and hydrazineto by blocking the ESIPT effect. [Display omitted] • A novel salomo-like dye probe with yellow-green fluorescence was synthesized. • Dye probes show obvious solvent-dependence based on spectroscopic testing. • Quickly identify CN− and N 2 H 4 by blocking the ESIPT effect due to the existence of resonance-assisted hydrogen bonds (RAHB). A novel bifunctional-group multi-purpose dye probe p-TNS has been designed and synthesized. The probe p-TNS has unique excited-state intramolecular proton transfer (ESIPT) and resonance-assisted hydrogen bonding (RAHB) coupled system, was confirmed to detect cyanide and hydrazine by blocking the ESIPT effect. Cyanide can change the fluorescence of the solution from bright green to orange-red (116 nm Stokes shift), while hydrazine causes the bright green fluorescence to be quenched. The recognition mechanism of the probe p-TNS to CN− and N 2 H 4 was proposed reasonably through spectral characterizations and theoretical calculations. Combined with theoretical calculations, it was speculated that the solvent dependence may be caused by the ICT effect in the molecule. The probe p-TNS could be prepared into test strips for the detection of cyanide and hydrazine. In addition, the probe molecule can also be used to detect trace amounts of cyanide in agricultural products, and respond to gaseous hydrazine by direct contact, indicating that the probe p-TNS has good practical application prospects. Therefore, this molecular framework provides a new way of thinking about detecting multiple target substances. [ABSTRACT FROM AUTHOR]

Two novel single-armed nitrogen-heterocyclic salamo-based fluorescent sensors with similar structures that can recognize Al3+ and CN− in aqueous systems, PDNS and PZNS, emit bright green–blue fluorescence in combination with Al3+ under a 365 nm UV light source and have detection limits as low as 6.25 × 10−9 and 1.26 × 10−9 mol·dm−3, respectively. [Display omitted] • Two nitrogen-heterocyclic chemosensors are investigated for recognition of Al3+. • Sensor PZNS can also recognition of CN−. • Sensor PZNS can work in a solution with 95% water content. • Nitrogen heterocycles were introduced into salamo-based molecules. • The identification mechanism are elaborated by 1HNMR, MS, and DFT. Two novel single-armed nitrogen-heterocyclic chemosensors with basically similar structures, PDNS and PZNS , were synthesized to specifically identify Al3+ in DMS:H 2 O (1:1 v/v) solution by fluorescence emission spectroscopy, and the colour of PDNS and PZNS changed from yellow to colorless when Al3+ was added under daylight. This is the first time that nitrogen-heterocyclic is introduced into salamo-based chemical sensor. At excitation wavelengths of 361 and 365 nm, solutions of PDNS and PZNS changed to intense green–blue fluorescence. Furthermore, it was found that PDNS / PZNS and Al3+ have excellent binding capacity, the lower limit of detection (LOD = 6.25 × 10−9/1.26 × 10−9 mol·dm−3) is also calculated. In addition, sensor PZNS can detect Al3+ in a solution system with up to 95% water content and applicable pH range is 3–12. Compared to other salamo-based sensors, PZNS and PDNS have broader detection conditions and wider utilities. PZNS can also identify CN− in fluorescence spectrum. PZNS can be used for detection of Al3+ in aqueous systems in daily production and life. [ABSTRACT FROM AUTHOR]