Study On Molecularly Imprinted Electrochemiluminescence Analysis For The Detection Of Clenbuterol

Clenbuterol(CLB)as adrenaline nervous stimulant is frequently added to animal feed because it can promote animal growth and improve lean percentage.And its abuse has caused lots of incidents of human poisoning.Nowadays a number of methods have been developed for CLB detection,such as gas chromatography-mass spectrometry(GC-MS),high-performance liquid chromatography(HPLC),liquid chromatography-mass spectrometry(LC-MS),capillary electrophoresis(CE)and enzyme-linked immunosorbent assay(ELISA).However,these methods still have some shortcomings,including time-consuming,complicated sample pretreatment and expensive instruments.Therefore,it is essential to establish a sensitive,accurate and rapid method for trace analysis of CLB.In this work,a simple,efficient and sensitive molecularly imprinted electrochemiluminescence sensor(MIECLS)based on reduced graphene oxide(rGO)and upconversion nanoparticles(UCNPs)was developed for trace determination of CLB.The MIECLS was constructed by the electro-polymerization of CLB and o-phenylenediamine on glassy carbon electrode(GCE)surface modified with UCNPs/rGO,realizing selective and quantitative determination for CLB.RGO generated by electrodeposition of graphene oxide not only acted as carrier for immobilizing UCNPs,but also had a significant impact in boosting electrochemiluminescence(ECL)response of UCNPs thanks to its high conductivity,superior electron transport rate and large specific surface area and thus the sensitivity of MIECLS can be improved.UCNPs as an advanced ECL emitter possessed wonderful ECL performance.And driven by electrostatic interaction,positively charged UCNPs and negatively charged rGO can be assembled together making ECL signal more stable.In the experiment,prepared electrodes were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),ECL and electrochemical impedance spectroscopy(EIS).Meanwhile,multiple factors that may affect the performance of the sensor were studied and optimized.Under the optimal experimental conditions,the ECL signal was proportional to the logarithm of CLB concentration in the range of 10 nM to 100 ?M with a low detection limit of 6.3 nM.The MIECLS exhibited good sensitivity,selectivity and favorable stability and was used to detect CLB in real samples.Traditional HPLC method was employed to validate the accuracy of MIECLS for detection results.And the results showed that there was no significant difference between the results of MIECLS and HPLC method,indicating enormous potential of the proposed MIECLS in the future of food safety detection.