title: Impedimetric characterization of adsorption of Listeria monocytogenes on the surface of an aluminum-based immunosensor.
abstract: The impedimetric characteristics of an immunosensor depend on the electrical properties of an immunosensor substrate. The impedimetric characteristics of an immunosensor compared with adsorption of Listeria monocytogenes were investigated on an aluminum surface insulated with an electrically resistive aluminum oxide layer. Antibody for L. monocytogenes (anti-L. monocytogenes) was immobilized on an aluminum surface that was insulated with a native air-formed aluminum oxide layer. The resistance of impedance (R) value of an aluminum-based immunosensor decreased, especially at 10(4) to 10(6) Hz, where the effect of the reactance of impedance (X) was minimal when L. monocytogenes was adsorbed on the immunosensor surface. The R value of the immunosensor at 81 kHz decreased proportionally to the concentration of L. monocytogenes from 1.3 to 4.3 log CFU mL(-1) . The adsorption of L. monocytogenes produced local protrusions on the immunosensor surface, causing physicochemical changes in the ionic layer formed on the immunosensor surface by a sinusoidal electrical signal input, which might help electrical current to flow and cause the R value to decrease.
authors.affiliation: Dept. of Food and Nutrition, Kookmin Univ, Seoul, 136-702, Korea; School of Environmental and Biological Sciences, Rutgers, the State Univ. of New Jersey, New Brunswick, NJ, 08901, U.S.A.
authors.forename: Changhoon
authors.initials: C
authors.lastname: Chai
authors.forename: Jooyoung
authors.initials: J
authors.lastname: Lee
authors.forename: Se-Wook
authors.initials: SW
authors.lastname: Oh
authors.forename: Paul
authors.initials: P
authors.lastname: Takhistov
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000737:chemistry*; D000907:Antibodies, Bacterial / Q000737:chemistry; D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D055598:Chemical Phenomena; D017097:Electric Impedance; D008089:Listeria monocytogenes / Q000302:isolation & purification*
chemical_list: D000907:Antibodies, Bacterial; D055910:Antibodies, Immobilized; D000535:Aluminum
keywords: aluminum oxide; immunosensor; impedance spectroscopy; pathogen detection