Electrochemical Behavior Of Artemisinin On Glassy Carbon Electrode Modified With Polythionine/Graphene/Silver Nanoparticles

Artemisinin extracted from Artemisia is an effective antimalaria drug as a sesquiterpene lactone compound containing the peroxide group, especially for chloroquine resistant Plasmodium falciparum infection and cerebral malaria. Currently, there are many analytical methods to determine artemisinin,but few papers are reported the detection of artemisinin with electrochemical method. In this paper, the determination of artemisinin is carried out by voltammetry using the glassy carbon modified electrode as the working electrode. Thionine is first electropolymerized on the glassy carbon electrode(GCE) to obtain the polythionine electrode(PTH). Graphite oxide suspension is coated and reduced to graphene(GN) on the PTH via electrochemical method. Then, silver(Ag) nanoparticles are electrodeposited on the surface of the above the electrode to fabricate the polythionine, graphene and Ag nanoparticles modified electrode(AgNPs/GN/PTH/GCE). The modified electrodes are characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS), the results show that polythionine, graphene and Ag nanoparticles are successfully modified on the surface of glassy carbon electrode. The electrochemical behaviour of artemisinin on AgNPs/GN/PTH/GCE is studied, displaying obvious excellent reduction peak potential.Moreover, the experimental conditions on the determination of artemisinin are optimized. The results show the ideal experimental conditions are B-R buffer solution as a supporting electrolyte, pH 7.1 solution and scanning potential range between-1.6 and 0 V. Meanwhile, the possible interference factors and the life of the modified electrode are also studied. The results indicate that 10-fold concentrations of artemisinic acid, 10-fold concentrations of Fine ammonia and so on barely influence the current response of artemisinin, the modified electrode keeps good stability. Under the optimized conditions, the modified electrode exhibits linear response to artemisinin in the concentration ranges from 3.2×10-8 to 1.0×10-6 mol/L, with a detection limit of 1.2×10-9 mol/L(S/N of 3). In addition, the reproducibility and selectivity of this modified electrode in the electrochemical reduction of artemisinin is also evaluated and given satisfactory results.