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A simple and unique dual-channel chemical probe (DH) was designed and synthesized, which not only realized sequential recognition of Cu2+ and CN− by colorimetric and fluorometric methods, but also realized fluorescence detection of CN−. When different cations (Co2+, Mg2+, Ni2+, Cd2+, Hg2+, Al3+, Ag+, Cu2+, Pb2+, Fe3+, Zn2+ and Ca2+) were added into the solution containing the probe molecule DH, only Cu2+ induced an observable change in the UV-vis and fluorescence spectra, indicating that the probe molecule can be applied for specific recognition of Cu2+. The anti-interference experiment of DH to Cu2+ showed that DH has good selectivity for detecting Cu2+, with a detection limit of 7.05 × 10−7 M. In particular, the fluorescence "ON–OFF–ON" process can be recycled by sequentially adding Cu2+ and EDTA, and the fluorescence intensity remained unchanged after ten times. This observation suggested that DH can achieve reversible highly sensitive response to Cu2+ and EDTA, and can be used as a hypersensitive logic gate for Cu2+ detection. More interestingly, when different anions (CH3COO−, SO32−, H2PO4−, ClO4−, NO3−, HSO4−, I−, Cl−, F−, Br−, N3− and CN−) were added into the solution containing DH and Cu2+, only CN− induced color change of the solution from red to yellowish green, and the fluorescence intensity greatly enhanced, indicating that DH-Cu2+ has a specific response to CN−. The anti-interference experiment showed that DH-Cu2+ has good selectivity for CN−, with a detection limit of 8.11 × 10−6 M. Moreover, the probe molecule DH can detect CN−, with a detection limit of 7.61 × 10−6 M. Experimental and theoretical methods were applied to deeply study the detection mechanism of DH, present great potential in practical application for ion test strips and HeLa cell imaging reagents. [ABSTRACT FROM AUTHOR]

A supramolecular sensor (APRA–G) was successfully constructed via host–guest interactions between a rhodamine hydrazone functionalized pillar[5]arene (APRA) and a bis-pyridinium derivative (G), which showed highly selective and sensitive detection of toxic Hg2+ through a dual-channel (colorimetric and fluorescent) model. The detection limits of fluorescence and UV-vis spectroscopy towards Hg2+ were 1.69 × 10−8 M and 4.07 × 10−7 M, respectively, which were calculated using the 3σ method. Interestingly, APRA–G could act as an excellent material for Hg2+ separation. Based on ICP (including inductively coupled plasma) data, the separation percentage of the supramolecular sensor (APRA–G) for mercury ions was up to 99.68%. [ABSTRACT FROM AUTHOR]

In this study, we developed a novel chemosensor (ATS) that contains the 5-(4-nitrophenyl)-2-furan group and α-naphthylamine for the dual-channel sensing of mercury ions. Under attack from mercury ions, the probe undergoes a blocked process; moreover, it broke the intramolecular charge transfer (ICT) state of the chemosensor, which can be confirmed by 1H NMR, IR and MS studies. We designed this probe to produce a significant change in the color and fluorescence intensity that can achieve naked eye recognition. The experimental results proved that the 5-(4-nitrophenyl)-2-furan group is a very good chromophore. In addition, the ICT state inhibited the fluorescence of naphthylamine. The fluorescent intensity changed significantly when naphthylamine was released. Moreover, high selectivity experiments revealed that the fluorescent sensor is specific to mercury ions even with interference by high concentrations of other metal ions. The test strips based on ATS were fabricated, which could act as a convenient and efficient mercury ion test kit. [ABSTRACT FROM AUTHOR]

A supramolecular sensor (APRA–G) was successfully constructed via host–guest interactions between a rhodamine hydrazone functionalized pillar[5]arene (APRA) and a bis-pyridinium derivative (G), which showed highly selective and sensitive detection of toxic Hg2+ through a dual-channel (colorimetric and fluorescent) model. The detection limits of fluorescence and UV-vis spectroscopy towards Hg2+ were 1.69 × 10−8 M and 4.07 × 10−7 M, respectively, which were calculated using the 3σ method. Interestingly, APRA–G could act as an excellent material for Hg2+ separation. Based on ICP (including inductively coupled plasma) data, the separation percentage of the supramolecular sensor (APRA–G) for mercury ions was up to 99.68%. [ABSTRACT FROM AUTHOR]