Modification of Nitrogen-Terminated Boron-Doped Diamond Electrodes with Gold Nanoparticles and Hemoglobin for Acrylamide Biosensors

Boron-doped diamond (BDD) was modified with gold nanoparticles (AuNPs) and hemoglobin (Hb) through nitrogen groups on the surface of BDD to produce an electrode with good selectivity, sensitivity, and affinity to be applied as an acrylamide biosensor. Prior to modification with Hb, the BDD was modified with AuNPs to increase the affinity of BDD with nitrogen termination (N-BDD) towards Hb. The electrochemical behavior of the hemoglobin-modified with gold nanoparticles on the surface of N-BDD electrode (Hb-AuNPs-N-BDD) in the presence of acrylamide was studied in comparison to hemoglobin-modified gold electrodes (Hb-Au). Cyclic voltammetry indicated the optimum concentration of Hb was obtained at 0.6 mg/mL in Hb-Au electrode and 0.02 mg/mL in Hb-AuNPs-N-BDD electrode. The responses were linear against the acrylamide concentration range of 0 - 30 mu M with an estimated LOD of 38.15 mu M at Hb-Au electrode and 13.10 mu M at Hb-AuNPs-BDDN electrode. The results indicated that Hb-AuNPs-N-BDD electrode has a better performance than Hb-Au electrode as the acrylamide sensors.