Effect of Pt-Ni Deposition Sequence in PtNi-Modified Boron-Doped Diamond on Catalytic Performance for Glucose Oxidation Under Neutral pH Conditions

With the increasing number of diabetic patients, considerable attention has been paid to developing metal nanomaterial glucose sensors for detecting under physiological pH conditions. In this work, Pt-Ni modified boron-doped diamond (BDD) electrodes were fabricated and achieved a continuous and stable response to glucose under neutral pH conditions. Besides, effects of the electrochemical deposition sequence on the morphology and electrocatalytic properties of the Pt-Ni bimetal had been found. Electrochemical performance tests showed that the Pt-Ni bimetal clusters prepared by the co-deposition (one step) method had higher stability and sensitivity for the glucose detection than those prepared by the two-step deposition method. The loss of the oxidation peak current of PtNi-BDD is 21.74% after 200 consecutive cyclic voltammetry cycles (2400 s). While Ni/Pt-BDD and Pt-BDD only maintained 55.8% and 60.03% of their initial current response after continuous 1200 s cyclic voltammetry. In addition, the sensitivity of PtNi-BDD was 110.375 μA cm -1 mm -1 in the range of 2-12 mM glucose concentration, which was 5.966, 15.49, and 6.13 times higher than that of Pt/Ni-BDD, Ni/Pt-BDD, and single metal Pt, respectively.