Label-free electrochemical immunosensor based on cerium oxide nanowires for Vibrio cholerae O1 detection.

This paper developed a label-free immunosensor based on cerium oxide nanowire for Vibrio cholerae O1 detection application. The CeO2 nanowires were synthesized by hydrothermal reaction. The immobilization of Anti-V. cholerae O1 onto CeO2 nanowire-deposited sensor was performed via an amino ester, which was created by using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, and sulfo-N-hydroxysuccinimide. The electrochemical responses of the immunosensor were studied by electrochemical impedance spectroscopy with [Fe (CN) 6] (3-/4-) as redox probe. A linear response in electron transfer resistance for cell of V. cholerae O1 concentration was found in the range of 1.0 × 10(2)CFU/mL to 1.0 × 10(4)CFU/mL. The detection limit of the immunosensor was 1.0 × 10(2)CFU/mL. The immunosensor sensitivity was 56.82 Ω/CFU · mL(-1). Furthermore, the parameters affecting immunosensor response were also investigated, as follows: pH value, immunoreaction time, incubation temperature, and anti-V. cholerae O1 concentration.