Study On Detection Of Ciprofloxacin In Water By Electrochemical Sensor

Antibiotics are greatly produced and widely used in China.Human and veterinary antibiotics enter the aquatic environment through different channels,and antibiotic pollution in the aquatic environment has been proven to be harmful to the environment.Ciprofloxacin（CFX）,as a widely used third-generation fluoroquinolone broad-spectrum antibiotic,is often detected in the water environment.With the increasing pollution of ciprofloxacin in water environment,the rapid detection of CFX has become very important.In this paper,two new electrochemical sensors were constructed to detect ciprofloxacin in water,and the reaction mechanism of antibiotics at the electrode interface was explored.The main results achieved are as follows:（1）Nitrogen plasma modification of glassy carbon electrode was used to construct an electrochemical sensor based on nitrogen plasma modification（NP-GCE）.X-ray photoelectron spectroscopy（XPS）analysis showed that the surface of NP-GCE was successfully introduced with N-active functional groups,and the different types of N-functional groups were analyzed.Atomic force microscopy（AFM）showed that the surface roughness of NP-GCE was not obvious,effectively controlling the increase in background current;the contact angle（CA）was used to investigate the hydrophilicity and hydrophobicity of the NP-GCE surface;the electrochemical impedance spectroscopy（EIS）was used to characterize the electron transfer ability of the NP-GCE.After optimizing each experimental parameter,the linear range of the sensor is 2.5×10^-7-1.0×10^-4 mol/L,and the detection limit is 8×10^-9 mol/L.（2）Laser-induced graphene（LIG）electrodes were prepared by laser-modified polyimide.Scanning electron microscopy（SEM）,raman spectroscopy（Raman）,and contact angle（CA）were used to analyze the interface morphology,material properties,and hydrophobicity of the electrodes before and after modification;electrochemical impedance spectroscopy（EIS）was used to characterize the electron transfer ability of the LIG electrode.Conditions such as modification power,experimental pH,and scanning rate were optimized.The linear range of the sensor was 2.5×10^-6-1.0×10^-4mol/L,and the detection limit is 8×10^-7 mol/L.The prepared paper-based electrode is flexible,foldable,and low in cost,which enriches detection method for the in-situ detection of ciprofloxacin in the water environment by the sensor.（3）In this study,we explored the stability,reproducibility,and anti-interference of electrochemical sensors based on nitrogen plasma and laser modified polyimide.The results showed that these two electrochemical sensors are feasible for the determination of CFX in actual water samples.