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An ICT fluorescence probe PIP-AH for colorimetric detection of hypochlorous acid and its applications in water samples and living cells. [Display omitted] • A novel fluorescent probe (PIP-AH) of HClO with ultrarapid-response (within 5 s), low detection limit (57.66 n mol·L–1) and the distinct colorimetric change (from green to blue) was synthesized. • PIP-AH can make into the portable test papers for colormetric determining HClO conveniently and be directly applied to detect HClO content in various actual water samples. • This probe was qualified for monitoring the variation of HClO levels in HeLa cells. Hypochlorous acid (HClO)/hypochlorite (ClO–) gets involved in many physiological and pathological processes. Although there is a lot of work that has been specifically reported in response to HClO, the ultrafast and colorimetric detection of HClO in the living body remains a challenge. Herein, we designed and synthesized a novel fluorescent probe PIP-AH based on the intramolecular charge transfer (ICT) mechanism, which showed an ultrarapid-response (within 5 s), the low detection limit (57.66 n mol·L–1) and the distinct colorimetric change (from green to blue) toward HClO titration in water solution. PIP-AH can make into the portable test papers for colorimetric determining HClO conveniently. Moreover, PIP-AH can be directly applied to detect HClO content in various actual water samples. Significantly, this probe was qualified for monitoring the variation of HClO levels in HeLa cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • The receptor CS-02 has been synthesized via simple Schiff's base reaction and specifically used for the detection of CN− ion. • The interaction ability of CS-02 towards CN− ion detection was found from Job's method (1:1, L:M) and Limit of detection is 10.39 × 10−5 M respectively. • Practical utility of CS-02 for specific detection of CN− was examined with different real samples and test kit. In the present work, a simple and highly selective colorimetric chemosensor (CS-02) , was designed and synthesized from 5(4) - amino-4(5) -(amino carbonyl)-imidazole hydrochloride and 5-(4-chloro phenyl) furan-2-carbaldehyde. The formation of the CS-02 (E)-5-amino-N-((5-(4-chlorophenyl) furan-2-yl) methylene)-1H-imidazole-4-carboxamide was confirmed by 1HNMR and Mass spectral techniques. The receptor CS-02 was found to show a colorimetric response of the colour change from Light yellow to Cyber yellow towards CN− ion, due to de-protonation and intra-ligand charge transfer. The receptor CS-02 interacts with cyanide in a 1:1 stoichiometric manner with a detection limit of 10.39 × 10−5 M. Receptor CS-02 could be recyclable by treatment with TFA. The sensing behaviour of the receptor was further enunciated by computational studies and it's also be efficiently used to detect trace amounts of cyanide present in Real samples such as tobacco, flax seeds, apple seeds, cigarette and Indian cigarette. Moreover, a visible colorimetric kit such as a test paper strip would be used in the CS-02 for practical applications. [ABSTRACT FROM AUTHOR]

In this article, we reported a new poly(diacetylenes)-based sensor (PDA-IBA) for silver ion detection and reduction through the chelation of imidazole moiety. The poly(diacetylenes) polymer functionalized with imidazole groups. As the concentration of silver ions in the solution increased, the PDA surface underwent oxidation concurrently with the reduction of silver ions was demonstrated through imidazole receptor. This chemical reaction resulted in a noticeable change in the color of the solution, shifting from blue to dark red. The limit of detection (LOD) was determined to be 0.034 mM. Zeta potential data analysis and electrochemical measurements further confirmed the PDA-IBA was capable to reduce Ag+ into Ag0. Moreover, the silver species produced were validated through inductively coupled plasma optical emission spectrometry (ICP-OES). Additionally, the color change observed in PDA-IBA as a response to silver ions was effectively demonstrated by integrating it into a paper-based sensor. This study introduces an innovative and promising approach for enhancing the capabilities of chemosensors in detecting and reducing Ag+. [Display omitted] • A highly sensitive and selective Ag + sensor, poly(diacetylenes)-based chemosensor PDA-IBA was synthesized. • The PDA-IBA polymer displayed a color change in the presence of Ag + through a chemical reduction process. • The silver ion's reduction was demonstrated by zeta potential data analysis and ICP-OES. [ABSTRACT FROM AUTHOR]

A new colorimetric fluorescent probe (MCy) for CN − is designed and synthesized based on triphenylimidazole-hemicyanine dyad. The probe shows high selectivity towards CN − in 100% aqueous solution even in the presence of other competitive anions such as F − , Cl − , AcO − , NO 2 − , H 2 PO 4 − , I − , SCN − , SO 4 2− , NO 3 − , HCO 3 − , Br − and S 2− . Upon nucleophilic addition of CN − to the indolium group, the probe displays large blue-shift in UV–vis spectrum and remarkable “turn-on” fluorescence owing to the disruption of intramolecular charge transfer. Meanwhile, the probe also undergoes a naked-eye discernible color change from orange to light pink in the sunlight as well as an obvious fluorescence color change from non-emissive to bright blue under a UV lamp. The detection limit of CN − in aqueous solution can be as low as 20.6 nM, which is much lower than the permissible level of CN − in drinking water according to the WHO. In addition, the probe has been successfully used to determine CN − in real water samples as well as to fabricate test paper kit for CN − detection. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sensor BMIP exhibits a naked eye colorimetric and fluorescence response towards Cu2+ ions. • BMIP responds rapidly toward Cu2+ ions with a low detection limit (7.84 nM). • The advances of BMIP as Cu2+ sensor have been verified for fingerprint imaging. • The sensor BMIP can be utilized for the determination of Cu2+ ions in environmental water samples. A new imidazole-based optical probe 2-((2-(benzo[ d ]thiazol-2-yl)hydrazono)methyl)-6-(4,5-diphenyl-1H-imidazol-2-yl)phenol (BMIP) as a colorimetric and fluorimetric chemosensor for detection of Cu2+ ions was synthesized and characterized by NMR spectra and mass spectra analysis. When exposed to Cu2+ ions in an aqueous environment even in presence of other cations, the probe BMIP exhibited striking color changes via a fluorescence-off process only for Cu2+ ions. The detection limit of Cu2+ was found to be 7.84 nM with response time as low as 10 s. In addition, BMIP -Cu2+ was found to be a reversible sensor with the addition of Ethylenediaminetetraacetic acid (EDTA). Experiments with test strips and with real water samples showed that the probe BMIP holds promise for identification of environmental ions. Density Functional Theory (DFT) computations with the Gaussian 16 software were employed to examine the BMIP sensing mechanism. The experimental findings were theoretically validated by DFT calculations. The application of BMIP as a Cu2+ sensor has been extended to live cell and fingerprint imaging. [ABSTRACT FROM AUTHOR]