Hydrogels of PANI doped with Fe3O4 and GO for highly stable sensor for sensitive and selective determination of heavy metal ions
K.S. Manjunatha Kumara, P. Shivakumar, V. Ganesh, Srinivasa Budagumpi, Shubhankar Kumar Bose, K. Hareesh, D. H. Nagaraju
Abstract
Heavy metal ion (HMI) pollution is threat to human health and environment. Here, a sensor for the electrochemical detection (ECD) of Pb +2 along with simultaneous detection of Cd +2 , Cu +2 and Hg +2 utilizing the synergic effect of dopants like graphene-oxide (GO) and iron oxide (Fe 3 O 4 ) into hydrogels of polyaniline (H-PANI/Fe-GO) displays an excellent square wave anodic stripping voltammetry (SWASV) performance towards Pb +2 , with an impressive limit of detection (LOD) of 5.15 nM. The oxidative peaks were observed for simultaneous detection at −0.7306, −0.4899, −0.0092 and 0.3417 V vs. Ag/AgCl for Cd +2 , Pb +2 , Cu +2 and Hg +2 with good sensitivity, reproducibility and stability. Additionally, H-PANI/Fe-GO sensor is effectively employed to detect Pb +2 in real water samples.