Temperature controllable electrochemical sensors based on horseradish peroxidase as electrocatalyst at heated Au disk electrode and its preliminary application for H2O2 detection

Abstract

In this paper, horseradish peroxidase (HRP) was successfully immobilized on heated Au disk electrode (HAuDE) by biotin-streptavidin specific interaction through HS-ssDNA-biotin self-assembled on HAuDE for investigation the electrocatalytic activity of HRP. With elevated electrode temperature, the significant temperature effect of the electrocatalytic activity of HRP for H₂O₂ reduction was demonstrated by using this bio-sensing platform. With an electrode temperature of 40 °C, a detection limit of 1.5 × 10^-6 mol L^-1 for H₂O₂ reduction could be obtained, which was more than one magnitude lower than that with an electrode temperature of 0 °C. Because HRP can be widely used as an enzyme label for amplification detection, this sensing platform can be broadly applied to analytical chemistry such as nucleic acid detection, and aptamer-based biosensors.

Keywords: Electrocatalysis; Electrochemical sensor; H(2)O(2); Heated Au disk electrode; Horseradish peroxidase (HRP).