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A simple thiocarbazone‐appended coumarin derivative 1 with high selectivity as a ratiometric fluorescence sensor towards Cu2+ and Zn2+ in a semi‐aqueous solution was synthesised and characterised. Upon the addition of Cu2+ and Zn2+, the emission of 1 solution undergoes a blue and red shift to 480 and 545 nm according to the intense blue and yellow colour under a 365‐nm ultraviolet lamp, respectively. Binding was confirmed by ultraviolet‐visible absorption analysis, fluorescence measurement, mass spectrometry, proton nuclear magnetic resonance, Fourier Transform‐infrared spectroscopy and density functional theory calculation. The results show that 1 coordinated with Cu2+ and Zn2+ in different modes, resulting in different ratiometric fluorescence responses. The detection limits of the sensor 1 for Cu2+ and Zn2+ were 100.8 and 11.5 nM, respectively. The association constants (Ka) of Cu2+ and Zn2+ with 1 were determined to be 5.59 × 104 and 5.08 × 104 M−1, respectively. Fluorescent microscopy experiments demonstrated that probe 1 has the potential to be used to monitor Zn2+ and Cu2+ in living cells. [ABSTRACT FROM AUTHOR]

A novel pyrazine hydrazone 1 has been designed and synthesized, which acts as a multiprobe for selective detection of Al3+, Mg2+, and Zn2+ in DMSO solution based on fluorescent enhancement with three different emission colors. The higher affinity of 1 toward Al3+ and Zn2+ compared with Mg2+ facilitates the establishment of a simple ratiometric fluorescent method for the detection of Al3+ and Zn2+ based on the 1 + Mg2+ system. Conversely, probe 1 selectively recognized Al3+ in DMSO-H 2 O cosolvent with a turn-on response, and the resultant 1 + Al3+ complex could determine F− via a fluorescence quenching signal. In addition, the probe is applied for imaging of Al3+ and F− in living cells. Image 1 [ABSTRACT FROM AUTHOR]

A rhodamine derivative ( R1 ) has been synthesized by an additive reaction of rhodamine 6G hydrazide with methyl 2-isothiocyanatobenzoate, which exhibits high selectivity and sensitivity as a fluorescent sensor toward Cu 2+ under physiological conditions. The detection limit of Cu 2+ ion is 47.2 nM. Moreover, R1 could sense Cu 2+ by “naked eye” with a color change from colorless to pink. This selective signaling behavior is not affected by other canions that might be present in the environmental samples. The application of the fluorescent sensor in monitoring intracellular Cu 2+ in HeLa cells was also demonstrated. [ABSTRACT FROM AUTHOR]

A rhodamine-2-thioxoquinazolin-4-one derivative ( R1 ) has been synthesized by an addition-elimination reaction of rhodamine 6G ethylenediamine with methyl 2-isothiocyanatobenzoate, which exhibits high selectivity and sensitivity as a fluorescent sensor toward Fe 3+ under physiological conditions. Moreover, R1 could sense Fe 3+ by “naked eye” with a color change from colorless to yellow. To test the practical use of the probe, the determination of Fe 3+ in real water samples was evaluated. The application of the fluorescent sensor in monitoring intracellular Fe 3+ in glioma cell line U251 has also been demonstrated. In addition, single crystal structures of R1 ·1·5H 2 O·0·5CH 3 CN, as well as the possible intermediate of R1 with Ag + and Hg 2+ ions were reported. [ABSTRACT FROM AUTHOR]

A new rhodamine-based derivative bearing pyrrole unit, R1 was synthesized as a dual-mode Cu 2+ -selective sensor via the rhodamine ring-opening approach and ratiometric displacement. A colorimetric and “off-on” signal for Cu 2+ through rhodamine ring opening in R1 and ratiometric fluorescent signal output when Cu 2+ displaces the bound Cd 2+ in the R1 -Cd 2+ complex can be observed. The application of fluorescent R1 to biological imaging was also demonstrated. [ABSTRACT FROM AUTHOR]

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 Cu2+ in H 2 O/CH 3 CN (99.5%, v/v) solution. Furthermore, the resultant Cu2+ complex selectively responded to pyrophosphate (PPi) among various anions based on fluorescent on–off signal. In addition, the probe could be used for detecting Cu2+ and PPi in HeLa cells. Image 1 • A quite simple pyrrole-quinazoline-based fluorescent probe for Cu2+ and pyrophosphate has been developed. • The crystal structures of the probe and its Cu2+ complex were reported. • The probe is an aggregation-induced emission enhancement active compound. • The probe has been used for imaging of Cu2+ and pyrophosphate in living cells. [ABSTRACT FROM AUTHOR]

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 N 2 H 4 has been synthesized, exhibiting a 'turn-on' response toward N 2 H 4 in CH 3 CN/H 2 O 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. Notably, the sensor could be used for the detection of N 2 H 4 in living cells. Unlabelled Image • A simple coumarin-based fluorescent sensor for hydrazine in either solution or aggregation states has been developed. • The sensor is an aggregation induced emission (AIE) active compound. • The probe could act as a fluorescent turn-on sensor toward hydrazine. • The probe has been applied in monitoring hydrazine in living cell. [ABSTRACT FROM AUTHOR]

A new colorimetric and fluorescence molecular chemosensor based on triazole hydrazone can be used as a multi-probe for selective detection of Al 3+ , Zn 2+ , and Cu 2+ by monitoring changes in the absorption and fluorescence spectral patterns. Results show that Al 3+ and Zn 2+ ions can induce remarkable fluorescence enhancement at pH 6.0 and pH 10.0, respectively, while the addition of Cu 2+ ions leads to a significant UV-visible absorption enhancement in the visible range at pH 6.0. In addition, the resultant Al 3+ complex could act as an 'on-off' fluorescence sensor for F - . The fluorescence sensor was also used to monitor intracellular Al 3+ , Zn 2+ , and F - in Hela cells., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)