Abstract: Using tetrabutyl titanate as a precursor，the nanometer Eu³⁺ doped TiO₂ was prepared by sol-gel method，and the property of luminescence of nano-powder was studied. The interaction of cypermethrin with Eu³⁺-TiO₂ was studied by absorption and fluorescence spectroscopy. The results indicated that the fluorescence intensity of Eu³⁺-TiO₂ was quenched by cypermethrin and the quenching rate constant（k_q）was 1.017×10¹¹ L/(mol·s) according to the Stern-Volmer equation，and the mechanism of quench had been discussed. Anewrapid method for detection ofpesticides was established according to that the fluorescence intensity of Eu³⁺-TiO₂ was proportional to cypermethrin concentration. The range of detection was 2.5×10^－10—2.5×10^－7 mol/L，the detection limit（3σ）was 2.5×10^－11 mol/L and the recovery was 89.25%—93.55%.

Key words: TiO₂, fluorescence, cypermethrin, fluorescence quenching

摘要： 以钛酸四丁酯为前体，采用液相法制备了水溶态纳米Eu³⁺掺杂TiO₂荧光探针，并对其发光性质进行了研究。通过紫外吸收和荧光光谱研究了它和氯氰菊酯之间的相互作用，结果发现，氯氰菊酯对Eu³⁺掺杂TiO₂的荧光具有猝灭作用，根据Stern-Volmer猝灭方程，计算出其猝灭常数为1.017×10¹¹ L/(mol·s)，并讨论了猝灭机理。依据氯氰菊酯浓度和Eu³⁺掺杂TiO₂的荧光强度成正比，建立了一种快速检测农药的新方法。其检测范围为2.5×10^－10～2.5×10^－7mol/L，检出限为2.5×10^－11mol/L，回收率在89.25%～93.55%之间。

关键词: 二氧化钛, 荧光光谱, 氯氰菊酯, 荧光猝灭