A new electrochemical sensor for simultaneous detection of sulfamethoxazole and trimethoprim antibiotics based on graphene and ZnO nanorods modified glassy carbon electrode

Abstract A novel electrochemical sensor based on graphene (GR) and ZnO nanorods (GR-ZnO/GCE) was developed to detect sulfamethoxazole (SMX) and trimethoprim (TMP) simultaneously. SEM image showed that ZnO had a rod shaped morphology. XRD result indicated a hexagonal wurtzite phase of ZnO nanorods. The electrochemical experiment results showed that the synergetic effect of GR and ZnO endowed the prepared sensor excellent electrocatalytic behavior towards the oxidation of SMX and TMP. SMX and TMP were detected by DPV method at 0.85 V and 1.06 V, respectively. Under the optimal conditions, the GR-ZnO/GCE showed superior wide linear responses in concentration range of 1–220 μmol/L for SMX and 1–180 μmol/L for TMP with the limit of detection (LOD) of 0.4 μmol/L and 0.3 μmol/L, respectively. In addition, the sensor has good stability, good selectivity, anti-jamming ability and reproducibility. We tested SMX and TMP in lake water, tap water, urine and serum with recovery between 93.2% and 108%. The proposed sensor has a good application prospect in biomedicine and environmental protection.