LAUSR

Magnetic bead-based electrochemical enzyme-linked immunoassay (MB-eElisa) represents an attractive approach to develop cost-effective systems that are suitable for sensing complex biological samples. Its sensitivity essentially depends on the transduction efficiency of enzyme catalytic reactions into electrochemical responses. Here, an ultrahigh signal-to-noise alkaline phosphatase (ALP)-based MB-eElisa system is developed with a renewable zinc oxide-reduced graphene oxide nanocomposite modified carbon paste electrode (ZnO@rGO/CPE). This biosensing system employs one antibody decorated MBs (MB-Ab1) to capture a model tumor marker - carcinoembryonic antigen (CEA) - from samples, while other antibody coated gold nanoparticles-ALP bioconjugates (Ab2-AuNPs-ALP) convert 1-naphthyl phosphate (1-NPP) into electroactive 1-naphthol (1-NP). Beneficial from the unique electrochemical properties of a ZnO@rGO/CPE, inlcuding nearly zero background and significantly enhanced responses toward the hydrolyzed 1-NP in the p...