A Sensitive Hydrogen Peroxide Sensor Based on Hemoglobin Immobilized on Gold Nanoparticles and 1,6-hexanedithiol Modified Gold Electrode

Abstract

Hemoglobin (Hb) was successfully immobilized on a gold electrode modified with gold nanoparticles (AuNPs) via a molecule bridge 1,6-hexanedithiol (HDT). The AFM images suggested that the HDT/gold electrode could adsorb more AuNPs. UV-vis spectra indicated that Hb on AuNPs/HDT film retained its near-native secondary structures. The electrochemical behaviors of the sensor were characterized with cyclic voltammetric techniques. The resultant electrode displayed an excellent electrocatalytical response to the reduction of hydrogen peroxide (H₂O₂). The linear relationship existed between the catalytic current and the H₂O₂ concentration ranging from 5.0 × 10⁻⁸ to 1.0 × 10⁻⁶ mol · L⁻¹. The detection limit (S/N = 3) was 1.0 × 10⁻⁸ mol · L⁻¹.

Keywords:

• Gold nanoparticles
• Hemoglobin
• 1,6-Hexanedithiol