Study On Detection Of Ofloxacin In Water By Electrochemical Sensor

Ofloxacin is a typical quinolone antibiotic with broad-spectrum antibacterial.It is widely used in humans and poultry as well as in agricultural cultivation.In recent years,OFL was frequently detected in the water environment.Meantime,antibiotic pollution has attracted human attention.The electrochemical sensor is a relatively novel analysis method,it is used to detect electrochemically active substances,which can avoid the disadvantages of the traditional detection method,and exert the advantages of convenient,efficient and on-line detection.Therefore,two electrochemical sensors were developed to detect ofloxacin in water,and the influence mechanism of pH on the electrochemical detection process was explored.The specific research work is as follows:?1?Graphene?Gr?and cellulose nanocrystals?CNCs?were sequentially loaded onto the surface of the glassy carbon electrode to prepare CNCs/Gr/GCE sensor.The modified electrode was characterized by atomic force microscopy?AFM?and scanning electron microscopy?SEM?,the interface properties can be determined by this characterization.The parameters included the modified volume of graphene,pH and scanning speed.The experimental results show that the sensor can effectively detect OFL.The concentration range of OFL is 7.5×10^-7-2.5×10^-4 mol L^-1,and the detection limit is 7.5×10^-7 mol L^-1.The CNCs/Gr/GCE sensor is stable and reproducible,and can effectively detect OFL in tap water and groundwater.?2?The glassy carbon electrode was modified by Ti₃C₂ nanomaterial to construct a new type of sensor.It was used to detect OFL in water,the modified electrode was characterized by the SEM,AFM and EDS measurements.The influence of sweeping speed,pH,rest time and common ions was discussed,the final detection limit is5×10^-7 mol L^-1,and the detection range was from 5×10^-7 to 5×10^-4 mol L^-1.The sensor device is feasible to detect actual water samples.?3?The pH of the buffer will cause the change of the DPV peak current,the falling speed of peak current under the acid condition is different with under the alkaline environment.Therefore,we first judge the interaction between the target pollutant and the electrode interface by molecular polarity method,and clarify the attenuation of the electrical signal of the OFL in the alkaline and acid environment.There is a difference because of the interaction between the hydrogen bonding force and the Coulomb electrostatic force.Through this research,we found that the identification of the existence form and the polarity of the target pollutant can quickly determine the optimal condition of the determination experiment,which is beneficial to the efficient detection and practical application of the electrochemical sensor.