Development of a disposable impedance biosensor and its application for determination of Escherichia co//0157:H7

摘要

The development of cost-effective, robust, and rugged biosensing devices is of great interest for point-of-care testing and on-spot monitoring. Here we reported a facile approach to build high-performance disposable impedance biosensor for sensitive and selective determination of Escherichia coli 0157.H7. Gold nanoparticles and graphene modified screen-printed carbon electrode was employed as the electrode substrate in this impedance biosensor. The Immobilization of anti-Escherichia coli 0157.H7 antibodies on electrode surface were performed by simple physical adsorption. Electrochemical impedance spectroscopy was used to detect Escherichia coli 015T.H7 captured on the disposable biosensor. Results show that the developed immunosensor possesses greatly enhanced sensing performance, such as wide linear range (1.5 * 103 -1.5* 107 cfu mL~1), low detection limit (1.5 * 103 cfu mL~1), and excellent specificity. The strategy of structurally integrating metal nanomaterials, graphene, and screen-printed electrode would provide new insight into design of disposable and high-performance immunosensors for routine sensing applications.