合成了平均粒径小于10nm的TiO2粒子,考察了在碱性条件下,纳米TiO2用溶胶一凝胶法修饰在铂电极上后,对鲁米诺电化学发光(ECL)的增敏作用。进一步研究了在纳米TiO2存在下,鲁米诺在铂电极表面的固定化及性能,所制得的电化学发光电极的发光强度与过氧化氢在一定浓度范围内成线性关系,可用于过氧化氢浓度的测定,检测下限达1×10^-8mol·L-1。以葡萄为应用对象,该检测体系可用于综合评估其抗氧化能力,以每克水果消耗过氧化氢毫克数(mgH2O2·g-1)为单位,葡萄肉汁为1.57,葡萄籽为4.72,即葡萄籽的抗氧化能力显著强于葡萄肉汁。
TiO2 nano-particles is synthesized and characterized by transmission electron microscope. The result shows that the average particle size of nanosized TiO2 is less than 10 nm. Its sensitization on electrochemiluminescence (ECL) of luminol in alkaline medium or sol-gel modified on platinum electrode is studied. The sensiti- zation is obvious whatever the TiO2 nano-particles are in solution or on the surface of electrode. The properties of the ECL electrode modified by TiO2 nano-particles and luminol sol-gel film are studied and the performance of the ECL electrode is good. The ECL intensity of the ECL electrode is linear with the content of the H202 in the range of 1×10^-7to 1×10^-5mol·L-1. Besides, the paper discusses the mechanism of the sensitization by UV-Vis spectrometry and examines the antioxidation ability of grape by using this ECL electrode.