光电化学竞争法检测生物素  

Photoelectrochemical Competitive Detection of Biotin

作　　者：刘世利[1,2] 陈守臻[1,2,3] 赵倩[1,2] 徐政虎[4] 李玉[3] 贾继辉[1,2] 郭良宏[5] 

机构地区：[1]山东大学医学院病原生物学研究所,济南250012 [2]山东省感染与免疫重点实验室,济南250012 [3]山东大学齐鲁医院,济南250012 [4]山东大学化学与化工学院,济南250012 [5]中国科学院生态环境研究中心环境化学与生态毒理学国家重点实验室,北京100085

出　　处：《分析化学》2013年第10期1477-1481,共5页Chinese Journal of Analytical Chemistry

基　　金：山东大学博士点基金(No.20120131120046);山东省优秀中青年科学家科研奖励基金(No.BS2010YY038);山东大学自主创新基金(No.2010TB014)资助

摘　　要：建立了光电化学系统竞争性检测生物素(Biotin)小分子浓度的方法。采用联吡啶钌[Tris(2,2'-bipyridine)ruthenium,Ru-bpy)]作为标记物,以氧化锡纳米颗粒为电极,草酸盐为电子供体还原标记物。在470 nm光激发下,联吡啶钌的外层电子吸收能量后由基态变为激发态,注入半导体氧化锡纳米颗粒电极的导带,形成光电流信号;草酸盐还原失去电子的联吡啶钌使其恢复初始状态,从而可以再次作为电子供体受激发产生光电流信号。在竞争性检测生物素(Biotin)浓度时,亲和素(Avidin)吸附到氧化锡纳米颗粒电极表面作为识别元件,在浓度大于0.5 g/L时能够达到最大的电极表面覆盖率。1μmol/L Ru-bpy-biotin与不同浓度Biotin组成的混合溶液与电极表面的Avidin发生亲和反应,光激发后检测光电流大小;当溶液中Biotin的浓度增加时,致使与电极表面Avidin结合的Ru-bpy-biotin量减少,在光照射下光电流信号降低。这一竞争性光电检测方法检测Biotin时,检出限为8μg/L。本方法可进一步扩展,应用于有机化合物的竞争性免疫检测。Quantitative detection of small molecules by a photoelectrochemical system was demonstrated in a competitive assay for biotin. The detection system was composed of ruthenium tris（bipyridine） （Ru-bpy） as the label, oxalate as the sacrificial electron donor to recycle the label, and tin oxide nanoparticle as the semiconductor electrode. Upon irradiation with 470 nm light, electrons of Ru-bpy were promoted to the excited state, and then injected into the conduction band of the tin oxide semiconductor, thus producing photocurrent signal. The oxidized Ru-bpy was reduced back to its original state by oxalate in solution, and was used again in the next cycle of signal generation. In the competitive assay of biotin, avidin was adsorbed passively on the tin oxide surface as the recognition element. Adsorbed protein was found to be stable under assay conditions, and reached maximum surface coverage when the concentration of avidin solution for adsorption was 0.5 g/L or higher. A mixed solution of 1 μmol/L tracer and various concentrations of biotins were reacted with surface- immobilized avidin. As biotin concentration was increased, less tracer molecules bound to avidin, leading to a reduction in its photocurrent signal. A detection limit of 8 μg/L biotin was obtained in the competitive assay. The method can be easily extended to the detection of competitive immunoassays for organic chemicals.

关 键 词：光电化学传感器 竞争性检测 生物素 联吡啶钌标记 

分 类 号：R341[医药卫生—基础医学]