Electrochemical impedance spectroscopy biosensor with interdigitated electrode for detection of human immunoglobulin A.
Interdigitated electrodes (IDEs) that have a series of parallel microband electrodes with alternating microbands connected together were utilized in electrochemical impedance spectroscopy (EIS) to build a label-free human immunoglobulin A (IgA) immunosensor. Anti-human IgA (anti-IgA) was employed as an IgA receptor and was covalently immobilized on the IDE surface through a self-assembled monolayer, as confirmed by atomic force microscopy. EIS measurements revealed that the specific adsorption of IgA onto the immobilized anti-IgA gave rise to a clear increase in the value of interfacial charge transfer resistance (R(ct)). A linear relationship between ΔR(ct) and the logarithm of IgA concentration was found for the concentration range of 0.01-100 ng/mL. No modulation of R(ct) was detected by immersing the sensor in solutions of other proteins such as human immunoglobulin G or bovine serum albumin, which confirmed a high selectivity of this immunosensor for IgA. These results demonstrated that the anti-IgA receptor simply immobilized on the IDE surface can provide a sensitive biosensor.
Division of Marine Technology, Tokyo University of Marine Science and Technology, 2-1-6 Etchujima, Tokyo 135-8533, Japan.
Ryuzo
R
Ohno
Hitoshi
H
Ohnuki
Huihui
H
Wang
Takuya
T
Yokoyama
Hideaki
H
Endo
Daiju
D
Tsuya
Mitsuru
M
Izumi
D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D058266:Dielectric Spectroscopy / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D007074:Immunoglobulin G / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007074:Immunoglobulin G