Study Of Ephedrine Hydrochloride Chemical Sensors

Ephedrine hydrochloride(EPh)is a sympathomimetic amine,which is mainly used as a conventional drug for the treatment of bronchial asthma and hypotension.Sometimes it is also used as an appetite suppressant.EPh may exhibits methamphetamine-like properties when present in excess in living organisms,including nervousness,rapid heartbeat,hypertension and epilepsy.So it was placed in the list of banned substances by the IOC Medical Committee.Furthermore,EPh also is an important ingredient in the manufacture of methamphetamine which make it included in the list of Class 1 easily controlled chemicals in China.In order to combat EPh abuse and drug crime,there is an urgent need for a simple and proven method for the analysis of EPh.In this work,two new methods for the analysis of EPh have been developed making full use of molecular imprinting technology,electrochemical methods,FRET(F?rster resonance energy transfer)theory and QDs.Details of the work are as follows:1.Based on molecular imprinting technology,a molecularly imprinted polymer(MIP)was synthesized by sol-gel method.The composite material formed by combining MIP with Nafion-MWCNTs was used as an EPh sensor and the analytical performance of the present sensor was evaluated.The evaluation results showed that the sensor has good selectivity,stability,reproducibility and interference resistance ablitity.Under optimal conditions,the linear range of the sensor for EPh detection was 0.18 μM-75 μM and the detection limit reached 0.072 μM(S/N = 3),surpassing much of the previously reported work.The sensor also showed good analytical performance in the analysis of real samples.The present work can not only provides a new method for the analytical detection of EPh,but also be extended as a general analytical method for the analysis of other substances.2.MPA-CdTe were prepared by aqueous phase synthesis using mercaptopropionic acid as the capping agent for CdTe QDs.The fluorescence quenching system of MPA-CdTe and rhodamine B was used as the basis and the "FRET principle" was used as a guide to prepare a "on-off" type EPh fluorescence sensor.The detection limit of EPh was 0.037 μM,which is higher than many reports.Satisfying results were obtained on the actual samples,and this study opens a new avenue for the design and construction of highly sensitive fluorescence sensors based on the QDs and FRET principle.