摘要
We applied the combination of in situ electrochemical liquid-phase microextraction and square-wave voltammetric stripping analysis for the first time as a highly sensitive and selective approach for the detection of dopamine. A mixed gel of graphene sheets and an ionic liquid of 1-octyl-3-methylimidazolium hexaflurophosphate (OMimPF(6)) was used as a micro liquid-phase to pre-concentrate dopamine by controlled potential electrolysis from an aqueous solution (as a donor phase), followed by square-wave voltammetric stripping detection. Under optimized conditions, a linear calibration curve was obtained in the range of 0.05 to 1.0 mu mol/L in the presence of excess ascorbic acid and uric acid. The detection limit has been found to be 8.0 nmol/L (S/N=3).