Electrochemical characterizations of Quaternarized Nanodiamond-Myoglobin Modified Electrode

Through a series of chemical reactions, quaternary ammonium salt derivatized nanodiamond, ND-CO-NH-CH2-CH2-N(CH3)3+ •I− (QAS-ND) was obtained, which was confirmed by FTIR, element analysis and electrochemical measurements. A mixture of solution of myoglobin (Mb) and QAS-ND was dropped on the surface of the glassy carbon (GC) electrode to prepare QAS-ND/Mb film modified electrode. In 0.1 M phosphate buffer solution (PBS, pH 7.0), Mb in the membrane exhibited direct electrochemical properties and good stability. The electrocatalytic property of the modified electrode toward H2O2 was also investigated. The results showed that the modified electrode could be used as a H2O2 biosensor to detect H2O2 quickly and accurately with a detection limit of 3.5 mmol/L (S/N = 3).

Graphical abstractAn amperometric biosensor based on a newly synthesized quaternarized nanodimond and myoglobin was fabricated. The direct electron transfer from the active center of myoglobin to the electrode surface was realized. The sensor was used to detect H2O2 rapidly and accurately with a detection limit of 3.5 mM.Figure optionsDownload full-size imageDownload as PowerPoint slide