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.

Biosensor for the detection of Listeria monocytogenes: emerging trends

“…A sensitivity of 0.825 kWcm 2 /(cfu/mL) and 1.129 kWcm 2 /(cfu/mL) and the LOD of 5 cfu/mL and 4 cfu/mL, respectively, was obtained using this method. Chai et al (2014) Figure 7A), were attached with the microfluidic chamber with three separate cells ( Figure 7B).…”