Multiplexed Anodic Stripping Voltammetry Detection of Heavy Metals in Water Using Nanocomposites Modified Screen-Printed Electrodes Integrated With a 3D-Printed Flow Cell.

Guo Zhao,Sidharth Modha,Ashok Mulchandani,Thien-Toan Tran,Mohammed Sedki,David Jassby,Nosang V Myung

doi:10.3389/fchem.2022.815805

Abstract

In this study, we present multiplexed anodic stripping voltammetry (ASV) detection of heavy metal ions (HMIs)—As(III), Cd(II), and Pb(II)—using a homemade electrochemical cell consisting of dual working, reference and counter screen-printed electrodes (SPE) on polyimide substrate integrated with a 3D-printed flow cell. Working and counter electrodes were fabricated by the screen-printing of graphite paste while the Ag/AgCl paste was screen-printed as a reference electrode (Ag/AgCl quasi-reference electrode). The working electrodes were modified with (BiO)2CO3-reduced graphene oxide (rGO)-Nafion [(BiO)2CO3-rGO-Nafion] and Fe3O4 magnetic nanoparticles (Fe3O4MNPs) decorated Au nanoparticles (AuNPs)-ionic liquid (IL) (Fe3O4-Au-IL) nanocomposites separately to enhance HMIs sensing. Electrochemical detection was achieved using square wave ASV technique. The desired structure of the flow electrochemical cell was optimized by the computational fluid dynamic (CFD). Different experimental parameters for stripping analysis of HMIs were optimized including deposition time, deposition potential and flow rate. The linear range of calibration curves with the sensing nanocomposites modified SPE for the three metal ions was from 0–50 μg/L. The limits of detection (S/N = 3) were estimated to be 2.4 μg/L for As(III), 1.2 μg/L for Pb(II) and 0.8 μg/L for Cd(II). Furthermore, the homemade flow anodic stripping sensor platform was used to detect HMIs in simulated river water with a 95–101% recovery, indicating high selectivity and accuracy and great potential for applicability even in complex matrices.

Highlights

With the development of global industrialization, especially, in the electronic and electrical industry, increasing amounts of heavy metal ions (HMIs) are inadvertently discharged into the environment
Two kind of sensing nanocomposites, i.e., (BiO)2CO3rGO-Nafion and Fe3O4-Au-ionic liquid (IL) were drop casted on the two working electrodes, where (BiO)2CO3-reduced graphene oxide (rGO)-Nafion was used for the detection of Pb(II) and Cd(II) and Fe3O4-Au-IL was used for the detection As(III)
The screen-printed electrodes (SPE) integrated two different working electrodes modified by (BiO)2CO3-rGONafion nanocomposite and Fe3O4-Au-IL nanocomposite for the Square wave stripping voltammetry (SWASV) determination of Cd(II)/Pb(II) and As(III), respectively, which efficiently enhanced the sensitivity of the sensor

Summary

Introduction

With the development of global industrialization, especially, in the electronic and electrical industry, increasing amounts of heavy metal ions (HMIs) are inadvertently discharged into the environment. Used analytical methods for the detection of HMIs include, atomic absorption spectroscopy (AAS) (Kenawy et al, 2000), atomic fluorescence spectrometry (AFS) (Wan et al, 2006), X-ray fluorescence spectrometry (XRF) (Galani-Nikolakaki et al, 2002) and inductively coupled plasma mass spectroscopy (ICP-MS) (Davis et al, 2007; Silva et al, 2009). These techniques have advantages of high sensitivity and selectivity; they have to be performed in a laboratory, which requires transportation of the samples to the laboratory, and use of expensive benchtop instrumentation by trained personnel. These conventional instruments and techniques require time consuming intricate operating procedures and sample preconcentration steps (Bi et al, 2010)

Methods

Results

Conclusion