Bio-functionalized Pt nanoparticles based electrochemical impedance immunosensor for human cardiac myoglobin

Abstract

We report the covalent immobilization of three-dimensional carboxyl-functionalized Pt(MPA) nanoparticles with myoglobin protein antibody by carbodiimide coupling reaction deposited onto an indium-tin-oxide-coated glass plate for the construction of a bioelectrode. This bioelectrode assembly was characterized by spectro/microscopic and electrochemical techniques. Electrochemical impedance studies of the bioelectrode showed significant changes in charge transfer resistance (R_et), predominantly in the low AC frequency region of <40 Hz, on immunoreaction with human cardiac myoglobin antigen (Ag-cMb). Ag-cMb detection in phosphate buffer exhibited a linear range of 0.01 μg mL⁻¹ to 1 μg mL⁻¹ with a sensitivity of 184.8 Ω cm² per decade.