Electro-oxidation of ascorbic acid at bismuth sulfide nanorod modified glassy carbon electrode

A novel bismuth sulfide nanorods modified glassy carbon electrode was developed and used for the measurement of ascorbic acid (AA). The modified electrode exhibited electrocatalytic response to the oxidation of AA. Compared with the bare glassy carbon electrode, the modified electrode presented a 150 mV shift of the oxidation potential in the negative direction and significant enhancement of the current response of AA. The response current exhibited good linear relationship for the concentration of AA in the range from 1.0 × 10−6 to 1.0 × 10−3 mol L−1, with the correlation coefficient of 0.997 and the detection limit of 8.3 × 10−7 mol L−1 on signal-to-noise ratio of 3. The method has been successfully applied to the determination of AA in tap water and some real samples and good recoveries were obtained. It is very promising for the Bi2S3 nanorods modified electrode to be used as an electrochemical sensor for the detection of AA.