Xiangqin Lin

This research found a cheap and efficient catalyst for electrooxidation of formaldehyde (HCHO). A CuO nano‐crystalline modified glassy carbon electrode (GCE) was fabricated and had an excellent electrocatalytic activity towards the oxidation of HCHO. Both the effect of potential scan rate and the effect of HCHO concentration on the electrocatalytic oxidation performance of the electrode were investigated. The amperometric current response of the electrode was proportional to HCHO concentration in the range of 1.0 µmol·L⁻¹–10.0 mmol·L⁻¹ with a detection limit (s/n=3) of 0.25 µmol·L⁻¹. The electrode was stable, showing the CuO nano‐crystlline is promising for applications in fuel cells and electrochemical sensors.

Two polymeric thin film modified electrodes, poly‐niacinamide/glassy carbon electrode (poly‐NA/GCE) and poly‐nicotinic acid/glassy carbon electrode (poly‐NC/GCE), have be fabricated at glassy carbon electrodes by simple electropolymerization of niacinamide (NA) in different potential scan ranges of cyclic voltammetry (CV). These two electrodes all showed catalytic ability towards the oxidation of dopamine (DA), uric acid (UA) and ascorbic acid (AA) by obvious reductions of overpotentials, giving well‐resolved voltammetric peaks, which allow simultaneously determination of DA, UA and AA. The poly‐NC/GCE showed even higher electrocatalytic activity than the poly‐NA/GCE. The electrochemical behavior of poly‐NC/GCE was investigated by CV and differential pulse voltammetry (DPV) for determination of DA, UA and AA. The linear ranges of the concentration for the determination of AA, DA and UA using DPV were 75–3000, 0.37–16 and 0.741–230 mol·L⁻¹, respectively. The slopes of the linear calibration curves for the detection were estimated to be 5.6, 1140 and 102 mA·L·mol⁻¹ for AA, DA and UA, respectively. The poly‐NC/GCE shows excellent sensitivity, good selectivity and antifouling properties.