Utilization of nitrogen self-doped biocarbon derived from soybean nodule in electrochemically sensing ascorbic acid and dopamine

Abstract

In this paper, a kind of soybean nodule-derived nitrogen-doped carbon (SNNDC) was prepared, characterized and applied to modify the assembled carbon paste electrode (CPE), to fabricate a novel chemical sensor for the detections of AA and DA. The electrochemical characteristics of SNNDC implied that it is an effective electron transfer mediator accelerating the electron transfer to CPE. The cyclic voltammetry measurements at different scan rates indicated that the electrochemical process on the electrode surface of the chemical sensor is a diffusion-controlled irreversible oxidation reaction of one-electron and one-proton for DA, and two-electron with one-proton for AA. The linear detection ranges of the chemical sensor for the detections of AA and DA were 5–3000 μM and 5–1000 μM with the detection limits of 1.90 μM and 3.18 μM, respectively, as determined by amperometric experiments. Both linear detection range and detection limit obtained are comparable or better than those of several modified electrodes reported recently. And the chemical sensor was also successfully applied to the detections of AA and DA in injection samples. This study suggested that the fabricated chemical sensor is a hopeful candidate to be used in the detection of pharmaceutical samples of AA and DA, and provides valuable reference information for the development of novel drug sensors in both clinical laboratory and food industries.