An electrochemical sensing platform was developed based on the composite of ionic liquid(1-butyl-3-methylimidazolium dicyanamide,[BMIM]N(CN)2,IL),multi-walled carbon nanotubes(MWCNTs) and polymeric matrix(chitosan,CS).Scanning electron microscope images showed that MWCNTs had a good dispersibility in the MWCNTs-IL-CS composite and formed a relative smooth film with unique structure.Electrochemical studies indicated that the MWCNTs-IL-CS composite provided a synergistic improvement on the electrochemical oxidation of dopamine(DA),uric acid(UA) and ascorbic acid(AA) by the decrease of their anodic over-potentials and the enhancement of their amperometric responses.The peak separations between UA and DA,DA and AA were 114 mV and 208 mV,respectively.Additionally,the MWCNTs-IL-CS composite modified glassy carbon electrode(MWCNTs-IL-CS/GCE) showed a good analytical performance in the simultaneous determination of DA,AA and UA.The calibration curves of 5.00-425 μmol/L,0.020-2.25 mmol/L and 0.050-10.0 mmol/L,and the detection limits(S/N=3) of 1.01,10.7 and 42.9 μmol/L were obtained for DA,AA and UA,respectively.With good selectivity and sensitivity,the present method is promising in the simultaneous determination of DA,AA and UA in real samples. |