Electrochemical behavior of gold nanoparticles modified nitrogen incorporated diamond-like carbon electrode and its application in glucose sensing

Gold nanoparticles (NPs) of 10-50 nm in diameter were synthesized on nitrogen incorporated diamond-like carbon (DLC:N) thin film electrode by electrodeposition. The deposition process of Au was investigated by cyclic voltammetry and chronoamperometry. The morphology of Au NPs was characterized by scanned electron microscopy. The potentiostatic current-time transients showed a progressive nucleation of Au and growth controlled by diffusion according to the Scharifker-Hills model. The electrochemical properties of Au-DLC:N electrode and its ability to sense glucose were investigated by voltammetric and amperometric measurements. The results showed that the Au NPs acted as nanoelectrodes improved the electron transfer and electrocatalytic oxidation of glucose on DLC:N electrode. The Au-DLC:N electrode exhibited fast sensing response, a linearity from 0.5 to 25 mM and a detection limit of 120 ¿m. The stable electrochemical properties of Au-DLC:N electrode hinted its potential application as a glucose biosensor.