以Co^(2+)掺杂纳米TiO_2为光催化氧化剂的原位光致化学发光分析方法研究及其应用

Photo-induced Chemiluminescence in-situ with Co～(2+)-doped TiO_2 Nanoparticle as Photo-catalytic Oxidant and Its Application

研究了Co2+掺杂TiO2纳米粒子在光信号诱导下产生的超氧阴离子自由基在纳米粒子表面的吸附和解吸特性.当以该纳米粒子为光催化氧化剂进行原位光致化学发光反应时,光诱导产生的超氧阴离子自由基通过扩散穿过纳米粒子表面的双电层到达本体溶液,与溶液中的化学发光试剂进行化学发光反应.由于超氧阴离子自由基在纳米粒子表面的吸附、解吸和双电层效应,使得光化学反应和其后的光生氧化剂的化学发光反应具有时间和空间的分辨特性.将Co2+掺杂TiO2纳米粒子光致化学发光反应的特点与鲁米诺化学发光体系结合,建立了一种原位光致化学发光反应的新方法,并提出了一种基于纳米技术调控化学发光反应的新思路.在最佳反应条件下,该方法对格列本脲响应的线性范围为2.0×10-8～1.0×10-6g·mL-1,检出限为6×10-9g·mL-1.

The superoxide anion was produced on the surface of Co2＋-doped TiO2 nanoparticles by the photo-induced effect and the characteristics of adsorption and desorption of the superoxide anion on the surface of these nanoparticles were studied. The desorption superoxide anion, photogenerated oxidant, may diffuse through the electric double layer formed on the surface of these nanoparticles into the solution and react with luminol in the solution to produce chemiluminescence （CL）. Therefore, this photo-induced chemiluminescence （PCL） signal on the surface of such nanoparticles had the time and space resolved performances with the nanoparticle as a photo-catalytic oxidant due to the hysteresis property of CL reaction. Based on these findings, not only a novel PCL method in situ was developed, but also a new idea of regulating CL based on nanotechnology was proposed. Under the optimum experimental conditions, the enhanced PCL signal was linear with glibenclamide concentration in the range of 2.0 ×10^-8~ 1.0 ×10^-6 g.mL^-1 and this new PCL method offered a 6 ×10^-9 g·mL^-1 detection limit for glibenclamide.