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 (H O ) 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.