Application of Gold Nanoparticles and Nano-Diamond Modified Electrode for Hemoglobin Electrochemistry

Abstract

In this paper nano-diamond (ND) decorated carbon ionic liquid electrode (CILE) was constructed by drop-casting, which was further modified by electrodeposited gold nanoparticles (AuNPs), hemoglobin (Hb) and Nafion orderly to obtain an electrochemical biosensor (Nafion/Hb/AuNPs/ND/CILE). The morphology of AuNPs/ND composite was checked by scanning electron microscopy. A pair of redox peaks of Hb on the modified electrode with good reversibility and symmetry appeared in cyclic voltammograms. The effects of pH and scan rate on Hb electrochemistry were further investigated to calculate the electrochemical parameters. The Hb based biosensor showed excellent electrocatalytic ability to the reduction of various substrates such as sodium nitrite, trichloroacetic acid and potassium bromate with the detection range from 0.07 to 2.60 mmol L-1, 1.00 to 500.00 mmol L-1 and 0.35 to 12.00 mmol L-1, respectively. Nafion/Hb/AuNPs/ND/CILE showed good reproducibility and stability, which was applied to the analysis KBrO3 content in real sea water samples.