Ultrasensitive electrochemiluminescence immunosensor based on Co-doped MoOx as co-reactant generator for the detection of amyloid β-protein

• Published in: Microchemical journal 2022-12, Vol.183, p.108036, Article 108036
• Main Authors: Zhang, Nuo, Liu, Shanghua, Jia, Yue, Zhao, Guanhui, Duan, Xiaoyi, Wang, Yaoguang, Zhang, Daopeng, Wei, Qin
• Format: Article
• Language: English
• Subjects: Amyloid β-protein; Au nanoclusters; Co@MoOx; Electrochemiluminescence immunosensor
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2022.108036

[Display omitted] •An ECL immunosensor was fabricated for ultrasensitive detection of amyloid β protein.•Co@MoOx was used as both sensing substrate and coreactant generator.•Co@MoOx showed good performance of electrolysis of water to produce oxygen.•Au NCs with ultrasmall size was cross-linked with ABEI to improve sensitivity. Herein, a novel electrochemiluminescence (ECL) immunosensor was constructed to detect amyloid β-protein (Aβ) by using Co2+ doped MoOx (Co@MoOx) as both sensing substrate and coreactant generator, Au nanoclusters and isoluminol (Au NCs-ABEI) as secondary antibody label. Co@MoOx showed good electrolysis performance of aquatic oxygen, and the dissolved oxygen just acted as a coreactant of the ABEI emitter in this system. Au NCs was synthesized from reduced glutathione, which had ultrasmall size and good biocompatibility. Bioconjugate Au NCs-ABEI was constructed on Au NCs surface by cross-linking ABEI with amino group on ABEI surface. Through modifying Co@MoOx and Au NCs-ABEI on the electrode successively, the ECL signal intensity of immunosensor increased, which showed high sensitivity for the detection of Aβ, with the detection range from 1.00 fg·mL−1 to 500 pg·mL−1 and the detection limit as low as 0.330 fg·mL−1. This strategy will provide some reference for the early diagnosis and prevention of Alzheimer's disease (AD) and detection of other disease markers.