基于P2 Mo18O6-62@Tb3+溶液可逆变色-荧光开关性质对维生素C和H2O2的光谱检测

基于变色多酸P₂Mo₁₈{\mathrm{O}}_{62}^{6-}与绿光Tb³⁺之间的功能互补及分子间能量转移的原理, 在维生素C(VC)的还原下, P₂Mo₁₈{\mathrm{O}}_{62}^{6-}@Tb³⁺溶液由浅黄色变为蓝色, 发生荧光猝灭; 相反, 在H₂O₂氧化下, 溶液的蓝色褪去, 荧光得以恢复, P₂Mo₁₈{\mathrm{O}}_{62}^{6-}@Tb³⁺溶液呈现出可逆的化学响应变色及荧光开关性质. 利用紫外-可见(UV-Vis)及荧光(PL)光谱法对VC浓度进行定量检测, 分别以800 nm处的吸光度和 547 nm处荧光强度的对数值对VC浓度作图, 获得光谱法对VC检测的线性方程, 检出限分别为3.40×10^-3和0.21 μmol/L; 利用UV-Vis及PL动力学方法对VC和H₂O₂检测的响应速度进行了考察, 响应时间分别为52和320 s; 通过UV-Vis光谱及动力学方法考察了VC检测的选择性及可重复使用性.

Spectral Detection for Vitamin C and H2O2 Based on the Reversible Color Change and Luminescent Switching Properties of P2Mo18O626-@Tb3+ Mixed Solution†

Based on the functional complementarity and energy transfer between the reversible discoloration polyoxoanions P₂Mo₁₈{\mathrm{O}}_{62}^{6-} and green luminescent Tb³⁺ ions, the color of the P₂Mo₁₈{\mathrm{O}}_{62}^{6-}@Tb³⁺mixed solution changed from light yellow to dark blue and as meanwhile the luminescence quenched under the reduction of VC. On the contrary, the dark blue color faded and the luminescence recovered correspondingly under the oxidation of H₂O₂. And the P₂Mo₁₈{\mathrm{O}}_{62}^{6-}@Tb³⁺ mixed solution exhibited a reversible chemical response discoloration and luminescent switching properties. The VC concentrations were quantitatively measured by UV-Vis and PL spectroscopy, and the corresponding linear equations were acquired by drawing VC concentrations with UV-Vis absorbance at 800 nm and fluorescence intensity at 547 nm. And the detection limits were 3.40×10^-3 and 0.21 μmol/L, respectively. The response rates of VC and H₂O₂ detection were investigated by UV-Vis and fluorescence kinetic methods, and the response time were 52 and 320 s, respectively. Finally, the selectivity and reusability of VC detection were studied by UV-Vis spectroscopy and kinetic methods.