Electrochemical detection of oxytetracycline employing sugarcane carbon modified graphite electrode.

The present study used CeO-CoO quantum dots@porous carbon/multiwalled carbon nanotube (CeO-CoO QDs@PC/MWCNT/GE) composites to modify graphite electrodes to fabricate high-sensitivity electrochemical sensors to detect the presence of oxytetracycline (OTC). The quantum dots were made from waste sugarcane bagasse. The electrochemical analysis demonstrated the superior electrochemical performance of CeO-CoO QDs@PC/MWCNT/GE, with a peak current density of 1.276 mA/cm. Electrochemical impedance spectroscopy (EIS) revealed lower impedance values for CeO-CoO QDs@PC/MWCNT/GE compared to other electrodes, indicating enhanced conductivity. The modified electrode exhibited an enlarged electrochemically active area, with values of 0.602 cm, almost seven times that of the bare graphite electrode (0.079 cm). The results showed that the CeO-CoO QDs@PC/MWCNT/GE had excellent performance for OTC detection, and its linear calibration range was 1.007 × 10 to 2.04 × 10 M (i.e., 0.005-0.1 ppm) and 1.007 × 10 to 1.209 × 10 M (i.e., 0.5-60 ppm). The limit of detection and limit of quantification were 1.23 nM (0.61 ppb) and 4.09 nM (2.03 ppb) (S/N = 3), respectively. The electrode demonstrated long-term stability for up to 7 weeks. This method provides a new way to prepare electrochemical sensors for OTC detection.