Cellular biosensor based on red blood cells immobilized on Fe3O4 Core/Au Shell nanoparticles for hydrogen peroxide electroanalysis

A core/shell Fe3O4/gold nanocomposite was prepared for immobilizing of red blood cells on a gold electrode via conjugation to a cysteamine monolayer. The hemoglobin in the film undergoes direct electron transfer at a formal potential of −330 mV and displays excellent electrocatalytic response to hydrogen peroxide, with a linear range from 9.6 µM to 2.6 mM. The limit of detection is 4.4 µM (S/N = 3). The Michaelis–Menten constant is 120 µM. Owing to its good biocompatibility, the biosensor exhibits good stability and acceptable reproducibility. The nanocomposite film provided a good matrix for the immobilization of cells and for the preparation of cellular biosensors.