Ionic liquid/carbon nanofibers/bismuth particles novel hybrid nanocomposite for voltammetric sensing of heavy metals
Résumé
A novel electrochemical sensor based on a nanocomposite of ionic liquid 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [EMIM][NTf2], carbon nanofibres, and bismuth particles modified carbon paste (BiPs-CNFs/[EMIM][NTf2]/CPE) has been proposed. Though the large active surface area and good electrical conductivity, the elaborated sensor exhibited excellent electroanalytical performances for the detection of heavy metal ions. In the presence of bismuth ions deposited by in-situ modification, the sensitivity of the BiPs-CNFs/[EMIM][NTf2]/CPE for the determination of Pb2+ and Cd2+ were significantly enhanced. At a concentration ranging from 2 to 120 μg L−1 and under the optimal working conditions the limits of detection for Pb2+ and Cd2+ were 0.12 and 0.25 μg L−1, respectively. The proposed electrochemical sensor has a good repeatability, reproducibility and selectivity for detection of Pb2+ and Cd2+ even in the presence of interfering ions. The BiPs-CNFs/[EMIM][NTf2]/CPE has been successfully applied for the detection of heavy metals in a real sample of well water with satisfactory results.