Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Biosens Bioelectron. 2016 May 15;79:482-7. doi: 10.1016/j.bios.2015.12.082. Epub 2015 Dec 24.
In the present work, an ultrasensitive sandwich-type electrochemical immunosensor based on a novel signal amplification strategy was designed for quantitative detection of alpha fetoprotein (AFP). Au nanoparticles with biocompatibility were electrodeposited on the surface of glassy carbon electrode (GCE) which can effectively capture and immobilize primary anti-AFP (Ab1) to significantly amplify the electrochemical signal. Graphene Oxide and CeO2 mesoporous nanocomposite functionalized by the 3-aminopropyltriethoxysilane supported Pd octahedral nanoparticles (Pd/APTES-M-CeO2-GS) were utilized as labels of detection anti-AFP (Ab2). Pd octahedral nanoparticles presented good catalytic activity towards the reduction of H2O2. Due to the large specific surface area and good adsorption properties of APTES-CeO2-GS nanocomposite, large amount of Pd octahedral nanoparticles could be immobilized, which could amplify the electrochemical signal and improve the sensitivity of the immunosensor. Under optimal conditions, the immunosensor exhibited wide linear range from 0.1 pg/mL to 50 ng/mL with a low detection limit of 0.033 pg/mL (S/N=3) for AFP detection. In addition, high sensitivity, excellent selectivity, good reproducibility and stability were obtained for the immunosensor, which has a promising application for quantitative detection of other tumor markers in clinical diagnosis.
在本工作中，设计了一种基于新型信号放大策略的超灵敏夹心型电化学免疫传感器，用于定量检测甲胎蛋白（AFP）。具有生物相容性的金纳米粒子被电沉积在玻碳电极（GCE）的表面，可有效捕获和固定一级抗 AFP（Ab1），从而显著放大电化学信号。通过 3-氨丙基三乙氧基硅烷支持的 Pd 八面体纳米粒子功能化的氧化石墨烯和 CeO2 介孔纳米复合材料（Pd/APTES-M-CeO2-GS）被用作检测抗 AFP（Ab2）的标记物。Pd 八面体纳米粒子对 H2O2 的还原具有良好的催化活性。由于 APTES-CeO2-GS 纳米复合材料具有大的比表面积和良好的吸附性能，因此可以固定大量的 Pd 八面体纳米粒子，从而可以放大电化学信号并提高免疫传感器的灵敏度。在最佳条件下，该免疫传感器对 AFP 的检测表现出从 0.1 pg/mL 到 50 ng/mL 的宽线性范围，检测限低至 0.033 pg/mL（S/N=3）。此外，该免疫传感器具有高灵敏度、优异的选择性、良好的重现性和稳定性，有望用于临床诊断中其他肿瘤标志物的定量检测。
