An immunosensor detects carcinoembryonic antigen by dual catalytic signal enhancer-hydrogen peroxide based on in-situ reduction of silver nanoparticles with dopamine and graphene high-load cobalt tetroxide

• Published in: Microchemical journal 2021-01, Vol.160, p.105602, Article 105602
• Main Authors: Liao, Xiaochen, Ma, Chaoyun, Zhao, Chulei, Li, Wenjun, Song, Yiju, Hong, Chenglin, Qiao, Xiuwen
• Format: Article
• Language: English
• Subjects: Dual catalysis; Electrochemical immunosensor; Polydopamine; Signal enhancer
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2020.105602

•A large number of electroactive substances loaded by rGO realize multiple amplification of signals.•AgNPs restored by PDA can be combined with a large number of secondary antibodies to achieve signal amplification again.•The prepared immunosensor has high sensitivity and low detection line, 0.17 pg/mL. In this work, we designed a gold nanoparticles (Au NPs) as a sensing platform, rGO/Co3O4@PDA-Ag NPs-Ab2 as a tag electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA). Graphene (rGO) rich in oxygen-containing groups can be more loaded with cobalt trioxide (Co3O4) and mild dopamine (DA) reduced silver nanoparticles (Ag NPs). The sensitive detection of CEA was obtained by differential pulse voltammetry (DPV) through the double-amplified electrochemical signal of hydrogen peroxide (H2O2) reduction catalyzed by Ag NPs and Co3O4. The linear range of the immunosensor is 0.0005 ng/mL–80 ng/mL, the minimum detection limit is 0.17 pg/mL. Immunosensor exhibit excellent repeatability, sensitivity and selectivity. This strategy has potential application value for initial clinical diagnosis.