Detection Of Antibiotics By Electrochemical Sensors Based On Nanocomposite Materials

Antibiotics are a kind of important medical drugs,which are widely used in many fields such as clinic and animal husbandry.With long-term unreasonable use and treatment,more and more problems are exposed,endangering human life and health and ecological environment.Therefore,the detection of antibiotics has become a research hotspot.Electrochemical methods have the characteristics of rapid,accurate,high sensitivity and low cost,and have important application prospects in the detection of antibiotics.In this paper,two kinds of electrochemical sensors were prepared based on nanocomposite materials for simultaneous detection of different antibiotics.The main contents are as follows:1.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 differential pulse voltammetric 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 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.2.For the first time,cefotaxime sodium(CEF)and nimesulide(NIM)were detected simultaneously by electrochemical method.The sensor was based on graphene and poly(L-cysteine)modified glassy carbon electrode(GR/p-(L-Cys)/GCE).When L-cysteine was electropolymerized by cyclic voltammetry,the reduction peak potential was at-0.5 V.SEM image showed that the morphology of poly(L-cysteine)was nanoscale.The electrochemical oxidation mechanism of CEF and NIM on GR/p-(L-Cys)/GCE was a 2-electron and 2-proton process.In the differential pulse voltammetric curve,the oxidation peak potentials of CEF and NIM were at 0.72 V and 0.97 V,respectively.Under the optimal experimental conditions,the linear ranges of GR/p-(L-Cys)/GCE for CEF and NIM were 1-60 μmol/L and 1-55 μmol/L,respectively,and the limits of detection were 0.49 μmol/L and 0.34 μmol/L,respectively.The sensor had good selectivity and stability.We detected CEF and NIM in tap water and lake water,the recovery was between 91%-109%,which provided a reference for the development of sensors with better performance.