Modifications of Epitaxial Graphene on SiC for the Electrochemical Detection and Identification of Heavy Metal Salts in Seawater

Abstract

The electrochemical detection of heavy metal ions is reported using an inexpensive portable in-house built potentiostat and epitaxial graphene. Monolayer, hydrogen-intercalated quasi-freestanding bilayer, and multilayer epitaxial graphene were each tested as working electrodes before and after modification with an oxygen plasma etch to introduce oxygen chemical groups to the surface. The graphene samples were characterized using X-ray photoelectron spectroscopy, atomic force microscopy, Raman spectroscopy, and van der Pauw Hall measurements. Dose–response curves in seawater were evaluated with added trace levels of four heavy metal salts (CdCl2, CuSO4, HgCl2, and PbCl2), along with detection algorithms based on machine learning and library development for each form of graphene and its oxygen plasma modification. Oxygen plasma-modified, hydrogen-intercalated quasi-freestanding bilayer epitaxial graphene was found to perform best for correctly identifying heavy metals in seawater.

Recent advances in the functionalization, substitutional doping and applications of graphene/graphene composite nanomaterials

“…138 However, recent approaches for the production of graphene depending on the requisite size, purity and efflorescence are reported in Table 2. 139–150…”

“…138 However, recent approaches for the production of graphene depending on the requisite size, purity and efflorescence are reported in Table 2. [139][140][141][142][143][144][145][146][147][148][149][150] 4 Functionalization of graphene leading to its enhanced structural versatility…”

Revisiting the Role of Sensors for Shaping Plant Research: Applications and Future Perspectives

“…Similarly, colorimetric nanosensors enable quick screening and visual detection for point-of-use applications. Recent reviews have highlighted the advances in nanomaterial-based optical sensors for heavy metal detection, with a focus on affordable and compact electrochemical nanosensors and smartphone-operated screen-printed electrodes (SPEs), among other technologies [ 85 ]. Developing reliable methods for heavy metal detection for environmental samples is crucial for ensuring public health safety and global homeland security.…”

Electrochemical and Colorimetric Nanosensors for Detection of Heavy Metal Ions: A Review

“…Among carbonaceous nanomaterials, carbon nanotubes and graphene are widely employed to modify screen-printed electrodes. Hajzus et al [98] investigated a sensitive platform for the selective voltammetric measurement of CdCl 2 , CuSO 4 , HgCl 2 , and PbCl 2 in seawater based on epitaxial graphene-modified SiC paper. They implemented machine learning models to accurately identify heavy metal types based on cyclic square wave voltammograms.…”