Electrochemical switch sensor toward ephedrine hydrochloride determination based on molecularly imprinted polymer/nafion-MWCNTs modified electrode

An electrochemical switch sensor toward ephedrine hydrochloride (EPh) determination was developed based on complex reactions and molecular imprinting (MIP) technique. The MIP was formed on a glassy carbon electrode (GCE) modified with Nafion-multi-walled carbon nanotube (Nafion-MWCNTs/GCE). The analytical performances of this sensor were evaluated using several electrochemical methods by measuring the response of EPh elution and re-adsorption in MIP. The working concentration range of this sensor was 1.8 × 10 −7 mol/L ~ 7.5 × 10 −5 mol/L with a detection limit of 7.2 × 10 −8 mol/L (S/N = 3). The sensor also displayed a fast response time of less than 180 s and good anti-interference ability towards several co-existing substances. The determination of EPh in spiked Saliva samples also receives satisfying results which suggest potential applications of the present sensor.