Non-Enzymatic Electrochemical Detection of Hydrogen Peroxide and Glucose through Using Copper(II) and Platinum(II) Complexes with Tridentate Ligand – Platinum Nanoparticles – Graphene Oxide Composite

Abstract

Two complex compounds [Cu(L)Cl2] (Cu-L) and [Pt(L)Cl]Cl (Pt-L) containing tridentate ligand (L = 2,6-bis(benzimidazol-2-yl)−4-hydroxypyridine) were prepared. After the successful immobilization of Cu-L and Pt-L on graphene oxide (GO), the electrochemical deposition of Pt nanoparticles was carried out on the modified surface. The resulting electrodes were demonstrated to possess exceptional electrocatalytic features towards the detection of H2O2, and glucose as indicated by the improvement in the cathodic peak response and a favourable shift in the reduction potential of each two reagents. The sensing devices exhibited promising electrochemical performance for the non-enzymatic measurement of H2O2, ranging from 0.01 mmol l−1 to 5 mmol l−1, and a considerably low LOD of 0.063 μmol l−1 and 0.113 μmol l−1 for Cu-L and Pt-L modified-GO decorated with Pt nanoparticles, respectively. Both sensors also showed exceptional sensitivity in the detection of glucose, with LOD of 0.054 μmol l−1 and 0.065 μmol l−1 in the concentration range of 0.01 mmol l−1 to 2 mmol l−1. The fabricated sensors also demonstrated decent sensitivity, long-term durability, and minimal interference capability. They were also tested for their ability to identify H2O2 and glucose in the actual biological fluid, demonstrating their practical use in routine H2O2 and glucose detection.