Graphene oxide/multi-walled carbon nanotubes/gold nanoparticle hybridfunctionalized disposable screen-printed carbon electrode to determine Cd(II) and Pb(II) in soil

Hui Wang,Guo Zhao,Zhiqiang Wang,Yuan Yin,Gang Liu,Fernando Bienvenido,Isabel M Flores-Parrad

doi:10.25165/j.ijabe.20191203.4300

Abstract

Cadmium (Cd) and lead (Pb) in soil or water environment cause the ecological destruction and environmental deterioration when their contents exceed the natural background values. To trace the concentrations of Cd(II) and Pb(II), a sensitive and selective electrode was developed using disposable screen-printed carbon electrode (SPE) immobilized with a composite film of reduced graphene oxide/carboxylation multi-walled carbon nanotubes/gold nanoparticle hybrid (RGO-MWNT-AuNP) through π-π bind. This highly conductive nano-composite layer, “RGO-MWNT-AuNP,” was characterized by scanning electron microscopy, UV-visible spectrometer, cyclic voltammetry, and electrochemical impedance spectroscopy. Square wave stripping voltammetry was applied to RGO-MWNT-AuNP/SPE to electroplate bismuth film and monitor the Cd(II) and Pb(II) simultaneously. To obtain high current responses, the detecting parameters were optimized. Under optimized conditions, the current responses showed a linear relationship with the concentrations of Cd(II) and Pb(II) in the range from 1.0 to 80.0 μg/L with a lower detection limit of 0.7 µg/L and 0.3 µg/L (S/N = 3), respectively. Finally, the prepared electrode was further employed to detect Cd(II) and Pb(II) in soil samples with good results. Keywords: electrochemical electrode, heavy metal contamination, screen-printed carbon electrode, graphene, gold nanoparticle, lead, cadmium, multi-walled carbon nanotube DOI: 10.25165/j.ijabe.20191203.4300 Citation: Wang H, Yin Y, Zhao G, Bienvenido F, Flores-Parrad I M, Wang Z Q, et al. Graphene oxide/multi-walled carbon nanotubes/gold nanoparticle hybridfunctionalized disposable screen-printed carbon electrode to determine Cd(II) and Pb(II) in soil. Int J Agric & Biol Eng, 2019; 12(3): 194–200.

Highlights

Heavy metals, including mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), Copper (Cu) and Arsenic (As)[1], are widely distributed in natural environment, which have serious hazards to human health and proved by many researches
3.1 Characterization of RGO-MWNT-aromatic compounds. Gold nanoparticles (AuNP)/screen-printed carbon electrode (SPE) The microstructure of the working electrode surface was investigated via the scanning electron microscope (SEM)
After SPE functionalized with RGO-MWNT hybrid, RGO and MWNT were homogeneously distributed on the working electrode surface, which owns a large specific surface area due to the special structure of RGO and MWNT

Summary

Introduction

Mainly derived from wastewater discharge, vehicle emissions, lead-acid batteries, fertilizers, mining and industrial wastes[1,4]. Many methods have been exploited and applied in testing organizations during the past decades, including atomic absorption spectrometry[7], inductively coupled plasma mass spectrometry[8,9], capillary electrophoresis[10], X-ray fluorescence spectrometry[11], and quantum dot[12] Most of these techniques have high sensitivity and selectivity, but they required bulk and expensive instrument, sophisticated operation and. Bare SPE has many drawbacks including low sensitivity and poor selectivity, which makes it hard to trace the super-low level of Cd(II) and Pb(II) Several new materials, such as nano materials[14], conductive polymer[15], ionic liquids[16] and biologic material[17], have been applied in the field of electrochemistry to improve the detecting performance. After optimized the electroanalytical parameters, the modified SPE was employed to detect the Cd(II) and Pb(II) using square wave stripping voltammetry

Materials and methods

Results and discussion

Conclusions