TiO2 Nanowire Bundle Microelectrode Based Impedance Immunosensor for Rapid and Sensitive Detection of Listeria monocytogenes

Abstract

A novel TiO₂ nanowire bundle microelectrode based immunosensor was demonstrated as a more sensitive, specific, and rapid technology for detection of Listeria monocytogenes. TiO₂ nanowire bundle was prepared through a hydrothermal reaction of alkali with TiO₂ powder and connected to gold microelectrodes with mask welding. Monoclonal antibodies were immobilized on the surface of a TiO₂ nanowire bundle to specifically capture L. monocytogenes. Impedance change caused by the nanowire−antibody−bacteria complex was measured and correlated to bacterial number. This nanowire bundle based immunosensor could detect as low as 10² cfu/ml of L. monocytogenes in 1 h without significant interference from other foodborne pathogens.