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[Display omitted] • Synthesis and characterization of a phenothiazine-linked pyridine acetonitrile compound (PZ-PY) through Knoevenagel condensation reaction. • Confirmation of PZ-PY's molecular structure via single-crystal X-ray diffraction, revealing a monoclinic crystal system with a P2 1 /c space group. • Absorbance and emission spectra of PZ-PY receptor at 431 nm and 608 nm, respectively. • PZ-PY's exceptional ability to recognize and bind cyanide ions, a toxic environmental chemical, with significant photophysical properties. • Confirmation of binding stoichiometry (1:1) through various analytical methods including Job's and HRMS spectroscopy. Determination of a relatively low limit of detection for cyanide ions (8.79 × 10 -8 M). • For practical application, the I3 receptor was investigated through the test strips, solid state, bioimaging (A547 cell line), detection of cyanide in diverse water samples and food samples. A phenothiazine-linked pyridine acetonitrile with a cyanoethylene bond PZ-PY has been synthesized by Knoevenagel condensation reaction and characterized by spectroscopic and analytical techniques. The structure of PZ-PY was confirmed through single-crystal X-ray diffraction studies; revealing its monoclinic crystal system with a P2 1 /c space group. The absorption maximum and emission spectrum of the PZ-PY receptor were observed at 431 and 608 nm respectively. Cyanide anion is one of the most prevalent chemicals in the environment, its toxic nature poses a constant threat to human daily life. The PZ-PY receptor's recognition of cyanide ions is associated with remarkable photophysical properties. The binding stoichiometry of PZ-PY-CN- was confirmed by Job's plot, B-H studies, 1H NMR titration, TD-DFT, and ESI-mass spectroscopy. The relatively low limit of detection was determined to be 8.79 × 10 -8 M in a linear range between 0 and 120 µL. PZ-PY receptor exhibits an aggregation-caused quenching (ACQ) nature with the increase in water fraction; it is stable between pH 2 to 11. Moreover, the practical applicability of PZ-PY was investigated through the test strip, solid-state, bioimaging (A547 cell line), detection of cyanide in diverse water samples (tap water, distilled water, and lake water), and food samples (sprouted potatoes, bitter almonds, and cassava). [ABSTRACT FROM AUTHOR]

[Display omitted] • Ninhydrin and Isatin-based chromogenic chemosensors selective for Cr3+ and Pb2+ ions were established. • NMR, FTIR, UV–vis and ESI-MS spectroscopy methods were used to confirm the probe and interaction of the probe with the analytes. • Probe L1 and L2 effective sense at colorimetric method was observed to be 2.80 × 10-6 M and 1.63 × 10-6 M detection limits. • Test Strip was designed to monitor the absorbance of Cr3+ and Pb2+ ions in real time analysis. • In a molecular logic circuit, the reversible and reproducible colorimetric switching off L1 and L2 was also discovered. A simple and easily synthesizable chromogenic small molecules probe L4 (2-(2-(benzo[ d ]thiazol-2-yl)hydrazono)-1H-indene-1,3(2H)-dione) and L5 (2-(2-(benzo[ d ]thiazol-2-yl)hydrazono)indolin-3-one) have been synthesized and characterized by various spectroscopy techniques such as FT-IR, NMR, and HRMS. The colorimetric naked eye detection of probe L4 showed a color change towards Cr3+ from orange color to pale yellow, whereas in case of L5 Pb2+ yellow to orange color was witnessed. The jobs plot analyses indicate the 1:1 binding stoichiometric for Cr3+ and 1:2 binding stoichiometric for Pb2+ ions with probes L4 and L5 respectively. The binding association constant (k a) values for L4 and L5 were found to be 6.651 × 10-5 M for Cr3+ and 6.493 × 10-5 M for Pb2+ ions. The limit of detection was found to be for Cr3+ (1.69 × 10−7 M) and Pb2+ (1.208 × 10−7 M) are far below than the limit set by the World Health Organization (WHO) for drinking water. Finally, the designed probes were applied for visible colorimetric test kits and real samples for rapid detection of Cr3+ and Pb2+ for all practical purposes, indicating their potential use in environmental samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple and novel Schiff base that is selective for cupric ions. • NMR, FTIR, and ESI-MS spectroscopy methods were used to confirm the interaction of the probe with the analytes. • Probe R1 effective sense at colorimetric method was observed to be 2.74 × 10-7 M detection limits. • The analysis kit was created to track the use of cupric ions in real-time. A novel sulfonohydrazide Schiff base colorimetric probe 4-methylbenzenesulfonohydrazide (R1) has been designed and synthesized which shows sensing recognition of Cu2+ in CH 3 CN:H 2 O (7:3, v/v) semi-aqueous medium. The prepared probe R1 was characterized using spectroscopic methods, including FT-IR, 1H NMR, and HRMS spectrometry. R1 exhibits an excellent selectivity to Cu2+ over other examined metal ions with a prominent colorimetric performance from colorless (345 nm) to crimson yellow (420 nm) under daylight. UV–vis titration experiment in the presence of different molar fractions of Cu2+ was used to perform a Job's plot analysis. The results showed that the stoichiometric ratio of the complex formed by R1 and Cu2+ was 2:1. A paper strip pre-stained with R1 solution was further fabricated and it also showed excellent sensing ability toward Cu2+ with a detection limit as low as 2.74 × 10-7 M with the naked eye, which represents better portability and operation simplicity that is favourable for on-site analysis of Cu2+ in water. The sensing mechanism was further verified with HOMO–LUMO energy levels were calculated using experimental and theoretical studies (DFT/TD-DFT), which correlated with good agreement. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multi-layer architecture of NiMOFs was synthesized and characterized by SEM, XRD, XPS, Raman, IR, and EIS. • The insertion of helical-shaped MWCNTs into NiMOFs has been done for enhanced electrocatalytic sensing applications. • The surface adsorption efficiency of the different modified electrodes was discussed. • The designed binder-free (GCE/MWCNT@NiMOFs) electrochemical probe exhibited a satisfactory limit of detection and wide linear response. • The designed electrochemical probe was successfully employed in real-world samples and achieved excellent recovery ranges with high reproducibility. Nitroimidazole-based drugs are widely used as an antibiotic for the treatment of anaerobic bacterial and parasite illnesses. The widespread use of these drugs in animal feed and the consequent environmental pollution have become significant concerns in recent years. Simple, sensitive, and rapid detection of the antibody in various real samples is demanding research interest. Herein, we report a Nickel-metal organic framework functionalized Multiwalled Carbon nanotubes modified glassy carbon electrode (MWCNT@NiMOFs) as an ultrasensitive and rapid voltammetric sensor for the detection of ornidazole (ORDZ) in a neutral pH solution. The MWCNT@NiMOFs were prepared using a microwave-assisted solvothermal technique accompanied by an ultrasonication method. The designed MWCNT@NiMOFs offered a low charge transfer resistance (R ct) of 141 Ω along with excellent electrocatalytic activity, and high current density at the lowered cathodic peak potential (-0.62 V vs Ag/AgCl) for ORDZ detection. The surface adsorption capacity (Γ s) in terms of surface excess and heterogeneous charge transfer rate constant (k 0) of the MWCNT@NiMOFs were calculated to be 3.29 × 10-9 mol cm−2 and 5.33 × 10-3 cm s−1, respectively. Under an optimal working condition, differential pulse voltammetry measurements of ORDZ have shown concentration linearity in a window, 100 nm to 10 µM range with excellent sensitivity, 5.69 × 10-5A µM−1 cm−2, and detection limit, 26 nM (3.3/s). The designed MWCNT@NiMOFs offered appreciable reproducibility, and repeatability up to 30 days of storage time. The real-time quantitative evaluation of ORDZ in human urine and tap water specimens was done along with ∼ 100 % recovery values. Since the new approach is simple, selective, and separation-free, it can be extendable to a variety of real-time practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • An easily designed R1 probe has been developed that demonstrates a rapid response to Cu2+ ions and possesses outstanding absorption and emission properties. • The ability to detect low levels of analytes with the lowest limit of detection (LOD) 3.23 × 10−9 M and quantification (LOQ) 10.79 × 10−9 M. • The R1 probe is capable of monitoring Cu2+ ions under physiological pH (2–10) conditions and exhibits specific selectivity towards cupric ion even in the presence of other competing ions. • The R1 probe was employed for the purpose of identifying the presence of Cu2+ ions in both the water and vegetable samples. In this work, we describe the synthesis of a Schiff base (R1) derived from furfural and 2-hydrazinobenzothiazole which displayed turn-off selective fluorescent chemo-sensing properties for Cu2+ ions in THF: HEPES buffer (9:1, v/v) solution. The molecular structure of the Schiff base (R1) was characterized by various spectroscopic techniques such as FTIR, 1H NMR, 13C NMR, and HRMS. Interestingly, R1 upon interaction with various metal cations displays highly selective colorimetric and fluorescent turn-off response to Cu2+ ions. The UV–Vis absorption study of the R1 with Cu2+ ions exhibits a noticeable color change from yellow to brown color with a redshift (∼60 nm). Upon the addition of Cu2+ ions emission quenching at 529 nm was observed in R1, and the limit of detection (LOD) and limit of quantification (LOQ) were found to be 3.23 × 10−9 M and 10.79 × 10−9 M. The mechanisms of probe R1 for sensing Cu2+ ions have been well demonstrated by Job's plot, Benesi-Hildebrand studies, and Density functional theory calculations (DFT). Owing to practical application, the Cu2+ ions were efficiently determined using a spike and recovery approach from real water and vegetable extract samples. Further, the developed R1 sensors were used for test strips application to detect the Cu2+ ions and achieved naked-eye detection. Therefore, these investigated results demonstrate that sensor R1 has great potential to detect Cu2+ ions in environmental analysis systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrazone based dual mode fluorescence sensor for Zn2+ ("turn-on") and Hg2+ ("turn off"). • Probe C1 selectively sense Zn2+and Hg2+ ions with their lowest detection limits 0.042 μM and 0.081 μM respectively. • The designed probe C1 was studied latent fingerprint analysis in various surfaces. • Live cell imaging studies was performed for probe C1 in presence and absence of Zn2+, Hg2+ ions. A facile Schiff base probe C1 has been developed and evaluated using 1H, 13C NMR, and mass spectroscopy. Fluorescence investigations were conducted to determine probe-sensing behavior. Probe C1 demonstrated sensitive, and selective recognition of Zn2+ and Hg2+ ions by using two distinct processes (i.e., chelation enhanced fluorescence effect and fluorescence quenching) over other cations in ACN-H 2 O (8:2, v/v). The Zn2+ and Hg2+ detection limits of 0.042 and 0.081 μM are achieved with the probe C1. C1 has a binding constant of 3.33 × 103 M−1 for Zn2+ and an emission quenching constant of 1.22 × 104 M−1 for Hg2+. A Jobs plot was used to determine the binding stoichiometry of C1 and Zn2+/Hg2+ ions ratio is 1:1. By using Zn2+/Hg2+ and EDTA additions alternately, the probe's reusability was investigated. Moreover, the probe was found to be highly cytocompatibility using an MTT assay in a mouse fibroblast cell line (NIH3T3). Further, the probe was found to visualize Zn2+ and Hg2+ ions inside the cells, indicating the potential application of the probe as an intracellular probe to detect Zn2+ and Hg2+ ions. The probe shows very good solid-state emission behavior, this motivates us to develop latent fingerprint detection and anticounterfeiting applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Inclusion complexes of FNA with various β-CDs were prepared by probe sonication. • The solid β-CDs:FNA inclusion complexes were prepared and characterized by FTIR, XRD, SEM, and TGA-DSC analyses. • Apparent high stability constant of β-CDs:FAN determined by phase solubility study. • The most favorable β-CDs:FNA complexes was confirmed by molecular docking studies. • β-CDs:FNA complexes showed an enhanced antibacterial and anticancer activities. This study explores the formation of inclusion complexes between the solubility enhancement of Flufenamic acid (FNA) and various β-Cyclodextrins (β-CD, Hβ-CD, Mβ-CD, and Sβ-CD) using ultrasonic probe sonication method. The investigation encompasses a multi-faceted analysis, employing UV–Visible, FTIR, XRD, FE-SEM, TGA-DSC techniques and molecular docking studies. The UV–Visible spectra reveal absorption peak shifts and binding constants (K a) indicate interaction strength, and thermodynamic parameters suggest spontaneous and favorable inclusion processes of β-CDs:FNA. Solid inclusion complexes of β-CDs:FNA were further characterized using FTIR, revealing alterations in functional groups indicative of complex formation. XRD analysis elucidates changes in crystallinity, while FE-SEM provides insights into morphological variations. Thermal stability is assessed through TGA-DSC, demonstrate the impact of inclusion on the complexes stability. Phase solubility diagrams illustrate the improved solubility of FNA in the presence of β-CDs. Mβ-CD:FNA exhibits the highest stability constant (1204 M−1), emphasizing its potential as an effective carrier. The binding energy of Mβ-CD:FNA (−46.72 kcal/mol) was lower than that of β-CD:FNA (−39.03 kcal/mol), Hβ-CD:FNA (−46.40 kcal/mol), and Sβ-CD:FNA (−46.29 kcal/mol), indicating that the hydroxypropyl group substitution enhanced the inclusion ability of β-CDs. Antibacterial activity studies against S. aureus and E. coli highlight enhanced efficacy of inclusion complexes with Mβ-CD:FNA (92.3 ± 0.18 % and 94.2 ± 0.17 %) demonstrating superior antibacterial activity. Cytotoxicity evaluations on HCT-116 cells reveal the safety profile of the β-CDs:FNA inclusion complexes, with Mβ-CD:FNA showing lower toxicity and high cell internalization compared to other formulations. The findings hold promise for applications in drug delivery, antimicrobial packaging, and the broader pharmaceutical and biotechnological fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Benzohydrazide-based chromogenic chemosensors for Hg2+ ion is established. • NMR, FTIR, UV–Vis and HRMS methods were used to confirm the ligand and complex. • PN effective sensing with Hg2+ ions were observed to be 3.08 × 10−7 M detection limit. • Test strip was designed to monitor the absorbance of Hg2+ ions in real time analysis. Metal ions play a crucial role in serving the proper functioning of living beings. Whereas Hg2+ ions are non-essential and toxic even at a minute level for living organisms. Thus, a simple colorimetric approach for Hg2+ ion detection is used. In this work, the synthesis of novel benzohydrazide-based Schiff base ligand (PN) as a sensor and exploring its colorimetric recognition ability. The ligand PN has been designed and synthesized via an economical and simple one-step condensation process. The as-synthesized PN ligand were successfully characterized by various spectroscopic techniques like 1H NMR, 13C NMR, FT-IR, HRMS and ICP-OES. ligand PN manifest outstanding selectivity for Hg2+ ions leaving the rest of the examined metal ions in mixed aqueous medium. A colour change of colourless to crimson yellow is prominent under UV light. The Job plot has shown formation of complex of 1:1 stoichiometric ratio of PN and Hg2+ ions; which is produced by conducting UV–vis titrations using different molar fractions of Hg2+ ions. Moreover, theoretical DFT calculations are validated by experimental data. Furthermore, pre-stained paper strips are furnished and it also showed excellent instantaneous Hg2+ naked eye sensing with a limit of detection as low as 3.08 × 10−7 M. [ABSTRACT FROM AUTHOR]