Dong Dong, Zheng Dong, Wang Fu-Quan, Yang Xi-Qiang, Wang Na, Li Yuan-Guang, Guo Liang-Hong, Cheng Jing
Anal Chem. 2004 Jan 15;76(2):499-501. doi: 10.1021/ac035184p.
Quantitative detection of a biological affinity reaction, the biotin/avidin recognition, was achieved using our newly developed photoelectrochemical analytical system. The system is based on the operation mechanism of the well-developed dye-sensitized photoelectrochemical solar cells and comprises a ruthenium tris(2,2'-bipyridine) (Ru-bipy) derivative as the photoelectrochemical signal-generating molecule, oxalate as the sacrificial electron donor, and tin oxide nanoparticle as the semiconductor electrode material. To perform the affinity reaction, avidin was immobilized on SnO(2) electrode by passive adsorption. Biotin-linked bovine serum albumin (BSA) was labeled with an NHS-ester derivative of Ru-bipy. After binding of BSA to the surface-immobilized avidin through biotin, photoelectrochemical measurement was carried out in the presence of oxalate. Anodic photocurrent was turned on and off repeatedly by control of incidental light. The action spectrum of the photocurrent resembled the absorption spectrum of Ru-bipy, proving the photocurrent was generated from the metal complex. A linear relationship between photocurrent and BSA concentration was obtained in the range of 1-100 microg/mL. This is the first case of quantitative photoelectrochemical detection of a biological affinity interaction.
利用我们新开发的光电化学分析系统实现了生物亲和反应——生物素/抗生物素蛋白识别的定量检测。该系统基于成熟的染料敏化光电化学太阳能电池的运行机制，由三（2,2'-联吡啶）钌（Ru-bipy）衍生物作为光电化学信号产生分子、草酸盐作为牺牲电子供体以及氧化锡纳米颗粒作为半导体电极材料组成。为了进行亲和反应，通过被动吸附将抗生物素蛋白固定在SnO₂电极上。用Ru-bipy的NHS-酯衍生物标记生物素连接的牛血清白蛋白（BSA）。在BSA通过生物素与表面固定的抗生物素蛋白结合后，在草酸盐存在的情况下进行光电化学测量。通过控制入射光，阳极光电流反复开启和关闭。光电流的作用光谱类似于Ru-bipy的吸收光谱，证明光电流是由金属配合物产生的。在1 - 100μg/mL范围内获得了光电流与BSA浓度之间的线性关系。这是生物亲和相互作用定量光电化学检测的首例。
