Indirect Detection Of Synthetic Antibacterial Drugs Based On Carbon Nanocomposite Electrochemical Sensor

Based on the current situation of aging population in China,the elderly are prone to adverse reactions such as central nervous system and gastrointestinal tract due to the physiological function changes of the elderly after using antibiotics;in the past few decades,antibacterials have made important contributions to the treatment of human and livestock bacterial infections.Due to the irrational use of antibiotics and environmental pollution caused by antibiotics discharged from drug prototypes,drug-resistant bacteria and drug resistance have become the status quo.Due to its unique physical and chemical properties,carbon nanomaterials are considered to be a better choice for the design and construction of electrochemical sensors.The modification of these substances is flexible,which greatly improves the analytical performance of antibiotics.In this paper,carbon nanocomposites are mainly used as modified materials to indirectly determine sulfamethoxazole,gatifloxacin and sulfamethoxine.The main contents are as follows:（1）Ultrasensitive detection of Sulfamethoxazole by glassy carbon electrode modified with silver oxide@multiwalled carbon nanotubes（Ag₂O@MWCNTs）nanocomposites.The Ag₂O@MWCNTs nanocomposite was prepared by in-situ precipitation method,and the Ag₂O@MWCNTs composite was modified onto the surface of the glassy carbon electrode by drop coating,and a new high-efficiency electrochemical sensor was constructed for indirect determination of sulfamethoxazole.The composite materials were characterized by scanning electron microscope（SEM）,ultraviolet spectrophotometry（UV-Vis）,and Fourier infrared spectroscopy（FT-IR）.The electrochemical behavior of sulfamethoxazole on the modified electrode was studied by electrochemical method,and the experimental conditions were optimized.The linear range of sulfamethoxazole was2.0×10^-11–1.0×10^-7 mol/L,and the detection limit was as low as 4.0×10^-12mol/L with indirect determination of sulfamethoxazole using differential pulse voltammetry（DPV）.Compared with other electrochemical measurement methods,it was ultrasensitive.The sensor was applied to the measurement of sulfamethoxazole in serum samples,the recovery rate was in the range of 96.27%-100.2%,and the results were satisfactory.（2）Indirect determination of gatifloxacin based on Alizarin@graphene oxide（AZ@GO）composite modified glassy carbon electrode.A new electrochemical sensor for the indirect determination of gatifloxacin was constructed by coating AZ@GO composite on the surface of glassy carbon electrode.The morphology of the modified material was characterized by scanning electron microscopy（SEM）.The composite was electrochemically characterized by electrochemical impedance spectroscopy（EIS）and cyclic voltammetry（CV）at 0.1 mol/L KCl of 5mmol/L K₃[Fe（CN）₆]and 5 mmol/L K₄[Fe（CN）₆].The electrochemical behavior of gatifloxacin on modified electrode was studied by electrochemical method,and the experimental conditions were optimized.The difference pulse voltammetry（DPV）was used to measure gatifloxacin indirectly.The linear range was 1.0×10^-7-1.0×10^-5 mol/L,the detection limit was 1.8×10^-8 mol/L,and the method had good stability,sensitivity and reproducibility.It was successfully applied to the measurement of gatifloxacin in serum samples,and the recovery rate of the spike was in the range of 99.83%-102.7%.（3）Indirect determination of sulfamonomethoxine based on Chlo ranil@Graphene composite modified glassy carbon electrode.A new electrochemical sensor for the indirect determination of sulfamonomethoxine was constructed by coating Chloranil@Graphene composite on the surface of glassy carbon electrode.The morphology of the modified material was characterized by scanning electron microscopy（SEM）.The composite was electrochemically characterized by electrochemical impedance spectroscopy（EIS）and cyclic voltammetry（CV）at 0.1 mol/L KCl of 5 mmol/L K₃[Fe（CN）₆]and 5 mmol/L K₄[Fe（CN）₆].The electrochemical behavior of sulfamonomethoxine on modified electrode was studied by electrochemical method,and the experimental conditions were optimized.The difference pulse voltammetry（DPV）was used to detect sulfamonomethoxine indirectly.The linear range was 5.0×10^-10-2.3×10^-9 mol/L,the detection limit was 3.0×10^-10 mol/L,and the method had good stability,sensitivity and reproducibility.The sensor was applied to the measurement of sulfamonomethoxine in serum samples,and the recovery of sulfamonomethoxine was in the range of 98.00%-101.6%.