Previously reported fluorescent sensors for Th 4+ experienced emission quenching or generated false positive signal upon aggregate formation in aqueous media. Herein, a simple and novel thorium sensor ( CDB-BA ) based on cyanodistyrene structure was designed and synthesized, which integrated the highly emitting characteristic of AIE effect and off-on response of PET modulation for the first time to construct the “turn-on” fluorescent probe for Th 4+ . Besides excellent selectivity, CDB-BA exhibited remarkable fluorescent enhancement which was linearly related to the concentration of Th 4+ in the range of 0.25–8 μM. The detection limit was attained 0.074 μM, which was lower than that of most previously reported sensors. The mechanism of tris-chelate complex of CDB-BA with Th 4+ was confirmed by mass spectra, IR spectra and DFT calculation. The excellent Th 4+ sensing ability of CDB-BA was successfully applied to detecting Th 4+ on TLC plates, in real water samples and living-cell imaging. This work suggested that the combination of AIE and PET photophysical mechanism could offer the merits of minimized background and enhanced signal fidelity to develop novel “turn-on” fluorescent probe in complicated aqueous environment and biological research.
Wenlong Fan,Ximing Huang,Xiaomin Shi,Zhuo Wang,Zhengliang Lu,Chunhua Fan,Qibing Bo
A big challenge is the discrimination of sulfhydryl-containing amino acids due to their structural similarity. We designed and synthesized a simple fluorescent probe 3 for specific detection of cysteine based on photo-induced electron transfer (PET). The acrylate and BODIPY moieties in probe 3 act as a reaction site and reporter group, respectively. So the synergistic effect of the substituent groups endows probe 3 very strong green fluorescence at 525 nm (λ ex = 500 nm). The cleavage reaction induced by cysteine leads to acrylate hydrolysis, and thereby triggers PET on, which effectively quench the fluorescence of 3 . Probe 3 exhibited a rapid response towards cysteine over homocysteine and glutathione . Probe 3 is successfully applied for sensing and imaging cysteine in vitro or in vivo cells with low cytotoxicity.
Herein, we designed the tyrosinase specific sensing probe NITYO with recognition unit, 3-hydroxy benzyloxy, that also regarded as an electron-rich group that quenches the naphthalimide core by PET effect. When tyrosinase exists and catalyzes the secondary oxidation of NITYO , the fluorescence emission goes red shift with “turn-on” signal. We hypothesized and confirmed these results through comprehensive analysis such as molecular orbital analysis, molecular docking and HRMS. To sum up, we achieve the tyrosinase detection by NITYO with highly sensitivity and selectivity. It can be used in food samples and in vivo bioimaging. Besides, NITYO performs superb linear fitting and lower detection limit (0.33 U/mL) within the range of 10–400 U/mL.
危险品化学品经营许可证（带存储）