A water-stable and pH-independent sensor for qualitative and quantitative detection of nicotine in urine solution and living cell was successfully developed. This material, named MB@UiO-66-NH 2 , can be synthesized by encapsulating methylene blue (MB) with a well-known metal−organic framework (MOF) UiO-66-NH 2 through a simple impregnation method. The fluorescence intensity of the system was significantly enhanced when a certain amount of nicotine was added. In the meanwhile, MB is reduced by reductive nicotine to form leucomethylene blue (LB). The proposed sensor displayed excellent selectivity and sensitivity toward nicotine with limit of detection (LOD) of 0.98 μM, which is comparable or even better than that of the electrochemistry detecting methods for nicotine. The obvious enhancement and blue shift of the emission arise from the photoinduced electron transfer (PET) from LB to the UiO-66-NH 2 . The photophysical properties and the sensing applications of MB@ UiO-66-NH 2 suggest that this composite can be acted as a sensitive, selective, recyclable, and fluorogenic sensor for nicotine determination in urine solution and living cell.

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A metal-free, photocatalyst-free, photochemical system was developed for the direct alkylation of thiophenols via electron donor− acceptor (EDA) complexes (K EDA = 145 M −1 ) between two reactants, Nhydroxyphthalimide esters as acceptors and thiophenol anions as donors, in the presence of a tertiary amine. The EDA complexes in the reaction system have a broad range of visible-light absorption (400−650 nm) and can trigger the reaction effectively under sunlight.

A deep-red fluorescence molecular rotor DpCy7 based on donor-two-acceptor modular system has been designed logically and synthesized for sensitive and selective response to viscosity changes and imaging of mitochondrial viscosity in living cells.

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