Direct Electrochemistry of Hemoglobin/Peptide-Carbon Nanotube Modified Electrode for Hydrogen Peroxide Biosensing Publisher



Sheikholeslam M^{1, 2, 3, 4} ; Nanda P³ ; Sanati A¹ ; Pritzker M³ ; Chen P^{3, 4} Show Affiliations
Source: Materials Letters Published:2023

Abstract

Mediatorless enzymatic biosensors based on direct electron transfer show promise due to their high stability and remarkable electrocatalytical performance. In this study, the direct electrochemistry of a glassy carbon electrode modified with hemoglobin (Hb) embedded in a hybrid layer of self-assembling EFK8 peptide and single-walled carbon nanotubes (SWNTs) was investigated. Electrochemical studies in 0.1 M phosphate buffer (PB) revealed that the immobilized Hb did not denature and retained its bio-catalytic activity. The resulting biosensor was used to detect and measure the hydrogen peroxide (H2O2) concentration in 0.1 M PB (pH 7.0), yielding a linear detection range from 20 to 960 µM and a detection limit of 7.54 µM (S/N = 3). The EFK8-SWNT hybrid layer shows promise as a biocompatible layer for simple non-covalent enzyme immobilization as the basis for future mediatorless enzymatic biosensors. © 2022