An AIRE-active far-red ratiometric fluorescent chemosensor for specifically sensing Zn and resultant Zn complex for subsequent pyrophosphate detection in almost pure aqueous media.

A simple Schiff-base fluorescent chemosensor (1) was synthesized by the reaction of 3-amino-pyrazine-2-carbohydrazide and 7-diethylamino-3-formylcoumarin; the sensor 1 displayed a notable green emission at 524 nm in DMSO and an aggregation-induced ratiometric emission (AIRE) at 555 nm in an almost buffered aqueous media (0.5% DMSO content). The AIRE of 1 was quenched following binding to Zn ions, while the fluorescence emission in the far-red region was evidently enhanced at 628 nm.

Pyrrole-quinazoline derivative as an easily accessible turn-off optical chemosensor for Cu and resultant Cu complex as a turn-on sensor for pyrophosphate in almost neat aqueous solution.

A simple chemosensor, 6-(1H-pyrrol-2-yl)-5,6-dihydro-benzo[4,5]imidazo[1,2-c]quinazoline (1), was synthesized via simple nucleophilic addition reaction coupled with Schiff base condensation. The probe 1 is aggregation-induced emission-active and could be used as an on-off fluorescence sensor toward Cu in HO/CHCN (99.5%, v/v) solution.

A novel 'turn-on' coumarin-based fluorescence probe with aggregation-induced emission (AIE) for sensitive detection of hydrazine and its imaging in living cells.

An aggregation-induced emission (AIE)- and intramolecular charge transfer (ICT)-based probe 1 (7‑hydroxy‑3‑(3‑methyl‑isoxazol‑5‑yl)‑chromen‑2‑one) that is highly selective for NH has been synthesized, exhibiting a 'turn-on' response toward NH in CHCN/HO solution. The detection limit of the probe was 2.90 ppb, which was evidently lower than the threshold limit value (10 ppb) recommended by the Environmental Protection Agency.

Ratiometric fluorescent probe based on pyrrole-modified rhodamine 6G hydrazone for the imaging of Cu in lysosomes.

A novel rhodamine-based Schiff base derivative was obtained via the simple condensation of substituted formyl-1H-pyrrole and rhodamine 6G hydrazone. Fluorescence resonance energy transfer enabled the subsequent use of the derivative as a naked-eye colorimetric and ratiometric fluorescent sensor for Cu in semi-aqueous solution, and the existence of the morpholine group enabled the further application of the sensor in imaging Cu in the lysosomes of HeLa cells.

Novel rhodamine-based colorimetric and fluorescent sensor for the dual-channel detection of Cu and Co/trivalent metal ions and its AIRE activities.

A rhodamine hydrazone 1 bearing coumarin moiety was designed and prepared. Compound 1 exhibited high selectivity toward Co and trivalent metal ions with fluorescence enhancement in CHOH solution. However, 1 selectively responded to Al in nearly pure HO media and was further applied to monitor Al in live cells.

A NIR sensor for cyanide detection and its application in cell imaging.

A novel 'D-π-A' sensor 1 has been designed and prepared via the condensation reaction of 3‑ethyl‑2‑methyl‑1,3‑benzothiazol‑3‑ium iodide and 5‑nitro‑o‑vanillin. Upon treatment with cyanide, sensor 1 exhibited a significant near-infrared (NIR) fluorescence quenching at 663nm. The MS, IR, H NMR and DFT methods confirmed that the response of 1 to cyanide is due to the nucleophilic addition reaction, which results in the inhibition of the Intramolecular Charge Transfer (ICT) process in the sensor.

A simple hydrazone as a multianalyte (Cu, Al, Zn) sensor at different pH values and the resultant Al complex as a sensor for F.

A new colorimetric and fluorescence molecular chemosensor based on triazole hydrazone can be used as a multi-probe for selective detection of Al, Zn, and Cu by monitoring changes in the absorption and fluorescence spectral patterns. Results show that Al and Zn ions can induce remarkable fluorescence enhancement at pH 6.0 and pH 10.

Quinoline containing acetyl hydrazone: An easily accessible switch-on optical chemosensor for Zn.

A simple chemosensor, namely, N-((quinolin-8-yl)methylene)acetohydrazide (1) was synthesized and used as an off-on fluorescence sensor, which exhibits high selectivity toward Zn in aqueous media. The probe has large Stokes shift of >200nm, and its detection limit for Zn is 89.3nM.

A highly sensitive and selective off-on fluorescent chemosensor for hydrazine based on coumarin β-diketone.

A coumarin-based sensor C1, namely 3-acetoacetylcoumarin was designed, synthesized and applied for hydrazine detection. Hydrazinolysis of the chemosensor gives a fluorescent coumarin-pyrazole product C1-NH [3-(3-methyl-1H-pyrazol-5-yl)coumarin], and thus resulting in a prominent fluorescence off-on response toward hydrazine under physiological conditions. The probe is highly selective toward hydrazine over cations, anions and other biologically/environmentally abundant analytes.

Both visual and fluorescent sensors for Zn(2+) based on bis(pyrrol-2-yl-methyleneamine) platform.

Two bis(pyrrol-2-yl-methyleneamine) chemo-sensors, 1, 3- and 1, 4-bis[3,4-dimethyl-5-ethyloxy -carbonyl-pyrrol-2-yl-methyleneamine]benzene (H2L(1) and H2L(2), respectively) have been synthesized and characterized, which exhibit high selectivity as off-on fluorescence sensors toward Zn(2+) in CH3CN/H2O (9:1, v/v) solution. The detection limits of both sensors are at the parts per million level. Moreover, the probes H2L(1) and H2L(2) could sense Zn(2+) by "naked eye" with a color change from colorless to yellow, and from yellow to dark yellow, respectively.