Li Yilin, Dai Hong, Zhang Qingrong, Zhang Shupei, Chen Sihong, Hong Zhensheng, Lin Yanyu
College of Chemistry and Chemical Engineering, Fujian Normal University, Fuzhou, Fujian 350108, China.
J Mater Chem B. 2016 Apr 21;4(15):2591-2597. doi: 10.1039/c5tb02525g. Epub 2016 Mar 29.
A versatile photoelectrochemical immunoassay protocol was designed for quantitative monitoring of tumor markers by utilizing the poly(dopamine)-sensitized titanium dioxide (TiO) signal crystal with an ordered mesoporous carbon support. Poly(dopamine) was introduced to alter the optical properties of the TiO signal crystal, thereby improving the visible light absorption and photoelectrical responses. More importantly, a new enzyme-like biomimetic catalyst was exploited as the signal amplifier to catalyze the reaction of hydroquinone. The generated product was deposited on the electrode surface and served as an efficient sacrificial electron acceptor, which could receive the photo-generated electrons of the excited semiconductor to assist the cathode photocurrent enhancement. Herein, a competitive-type immunosensor was achieved through the biomimetic catalyst labeled prostate specific antigen competing with the target antigen of different concentrations to react with the specific antibody anchored on the poly(dopamine)-sensitized TiO signal crystal. Under optimal conditions, the photocurrent decreased with increasing target concentration in a dynamic working range from 1 × 10 ng mL to 50 ng mL, which provided a new photoelectrochemical method for tumor markers analysis.
设计了一种通用的光电化学免疫分析方法，通过利用具有有序介孔碳载体的聚多巴胺敏化二氧化钛（TiO₂）信号晶体来定量监测肿瘤标志物。引入聚多巴胺以改变TiO₂信号晶体的光学性质，从而改善可见光吸收和光电响应。更重要的是，一种新型的类酶仿生催化剂被用作信号放大器来催化对苯二酚的反应。生成的产物沉积在电极表面并作为有效的牺牲电子受体，其可以接收激发半导体的光生电子以协助增强阴极光电流。在此，通过仿生催化剂标记的前列腺特异性抗原与不同浓度的靶抗原竞争，与锚定在聚多巴胺敏化的TiO₂信号晶体上的特异性抗体反应，实现了竞争型免疫传感器。在最佳条件下，在1×10⁻⁹ ng mL⁻¹至50 ng mL⁻¹的动态工作范围内，光电流随靶浓度的增加而降低，这为肿瘤标志物分析提供了一种新的光电化学方法。
