A novel sensor for the determination of Hg2+ in waters based on octadentate ligand immobilized multi-walled carbon nanotube attached to paraffin wax impregnated graphite electrodes (PIGE)

作者：Gayathri Jayagopi; Selvan Kumar Sangeetha; Narayanan Sangilimuthu Sriman^*

来源：Journal of Solid State Electrochemistry, 2018, 22(9): 2879-2888.

DOI：10.1007/s10008-018-3984-1

• Chemically modified electrode
• Octadentate ligand
• Multi-walled carbon nanotubes
• Mercury
• Water samples

In this work, the synthesised octadentate ligand immobilised multi-walled carbon nanotubes (MWCNTs) modified electrode as an electrochemical sensor of Hg2+ is reported. The octadentate/MWCNTs composites were coated on the polished surface of paraffin impregnated graphite electrode for fabricating the enhanced electrochemical sensing platform for Hg2+ determination. The octadentate ligand contains four N and four O donor atoms which coordinate with the metal ion in stripping medium have been investigated. Surface morphology of the fabricated modified electrode was studied using scanning electron microscope (SEM). The modified electrode was characterised by electrochemical impedance spectroscopy (EIS) and square wave anodic stripping voltammetry (SWASV). Further various factors such as preconcentration time, effects of pH and different electrolytes were optimised for the detection of Hg2+. Under the optimised condition, anodic stripping voltammetry of Hg2+ showed a response in a linear range from 2.4 - 180 nM and the limit of detection was 0.8 nM for Hg2+ (S/N = 3). Interference studies with Cd2+,As3+,Cu2+, Ag+,Ni2+,Fe3+,Zn2+,Sn2+ and Pb2+ showed an insignificant effect on the electrochemical response of Hg2+. The proposed modified electrode exhibited an excellent performance with good reproducibility, selectivity and stability. The practical application of the modified electrode was also evaluated by the detection of Hg2+ in well water and lake water samples with good recovery results.

• 出版日期2018-9