A boron-doped diamond electrode decorated with hemoglobin-modified platinum nanoparticles as a biosensor for acrylamide detection

Acrylamide (AA) is a neurotoxin and potential carcinogen. It has been found in various thermally processed foods, e.g., potato chips and biscuits. Thus, simple, rapid, and sensitive methods for AA detection are needed to ensure food safety. Herein, the fabrication of a highly stable AA biosensor is presented. A boron-doped diamond (BDD) was modified by Pt and hemoglobin. In the first step, platinum nanoparticles (Pt NPs) were chemically seeded onto the BDD surface using NaBH as a reducing agent. The electrochemical overgrowth of these Pt NP seeds was conducted at a constant potential of -0.2 V in a 1 mM Pt solution. Then, rapid thermal annealing (RTA) of the BDD/Pt NP composite was conducted at 700 °C under N atmosphere to enhance its stability. After RTA, BDD/Pt NP was electrochemically activated between -0.5 and 1.5 V. Then, further overgrowth was performed using a deposition voltage of -0.2 V to renew the BDD/Pt NP surface. Finally, 0.15-mM hemoglobin was used to modify BDD/Pt NP. The characterization of the resulting surface was performed using scanning electron microscopy. The biosensor exhibited an optimal response (limit of detection = 0.012 nM) at pH 4.9 in a 0.2-M acetate buffer solution.