Study On The Detection Of Chloramphenicol And Ofloxacin In Water By Electrochemical Sensor

Antibiotics play an important role in the treatment of infectious diseases in humans and animals.However,most antibiotics will enter the water environment with human activities and will threaten human health and even ecological balance.Therefore,it is very important to develop a fast and convenient antibiotic detection technology.In this paper,two electrochemical sensors are constructed to detect the typical antibiotics chloramphenicol（CAP）and ofloxacin（OFX）in the water environment.The main results are as follows:（1）On the basis of laser-induced graphene paper-based electrodes（LIG）,we combined modification of nano silver particles（Ag NPs）,nano titanium dioxide particles（TiO₂ NPs）and sodium carboxymethyl cellulose（CMC）composite materials.An Ag/CMC@TiO₂/LIG electrochemical sensor was developed for the sensitive detection of CAP.The electrode was characterized by using scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier infrared spectroscopy（FT-IR）,and contact angle analysis methods.The results showed that the bimetallic nanoparticle modification would have a better synergy catalytic effect,and the use of CMC can improve the hydrophilicity of the electrode and disperse TiO₂ NPs.Under optimized experimental conditions,the line range of Ag/CMC@TiO₂/LIG sensor to detect CAP is0.01-100μmol/L（3.23μg/L-32314μg/L）,and the detection limit is 0.007μmol/L（2.26μg/L）.（2）A new type of electrochemical sensor based on the rare earth element samarium（Sm）and organicβ-cyclodextrin（β-CD）composite material modified LIG electrode was developed to effectively detect the antibiotic OFX in the water.The morphology and structure ofβ-CD/SmOx NPs/LIG were studied by SEM,TEM,X-ray energy spectroscopy（EDS）,FT-IR,X-ray photoelectron spectroscopy（XPS）and contact angle.Cyclic voltammetry（CV）,electrochemical impedance spectroscopy（EIS）and linear scan voltammetry（LSV）were used to evaluateβ-CD/SmOx NPs/LIG,and the results showed that the electrode has good electrochemical performance.Under optimized experimental conditions,theβ-CD/SmOx NPs/LIG electrochemical sensor showed a low OFX detection limit of 0.005μmol/L（1.81μg/L）,and the linear response range was 0.005-1.0μmol/L and 1.0-120.0μmol/L（1.81-361.4μg/L&361.4-43364.2μg/L）.（3）It is explored that Ag/CMC@TiO₂/LIG andβ-CD/SmOx NPs/LIG electrochemical sensors have good anti-interference,stability and reproducibility.The results of spiked water samples showed that the relative standard deviation（RSD）of Ag/CMC@TiO₂/LIG for CAP detection was less than 3%,and the recovery rate was between 93.6%and 105.7%.The RSD of OFX detected byβ-CD/SmOx NPs/LIG was no more than 7.1%,and the recovery rates of blank addition in lake water samples were 96.00%-101.90%,and tap water samples were 98.00%-107.30%.The experimental results show that the two electrochemical sensors constructed are feasible for the determination of antibiotics in actual water samples.