An electrochemically reduced graphene oxide chemiresistive sensor for sensitive detection of Hg2+ ion in water samples

Abstract

Divalent mercuric (Hg) ion is one of the most prevalent forms of mercury species in waters with high toxicity and bioaccumulation in the human body, for which sensitive and selective detection methods are highly necessary to carry out its recognition and quantification. Here an electrochemically reduced graphene oxide (RGO) based chemiresistive sensor was constructed and used for the detection of Hg ion in various water samples. Monolayer GO sheets were assembled onto interdigitated electrodes, followed by reduction through linear sweep voltammetry and then modification with a single-stranded DNA aptamer. The electrochemically derived RGO based sensor showed selective response to as low as 0.5nMHg ion in presence of other metal ions and matrices. A comparison between chemiresistive sensors prepared with electrochemically and chemically derived RGO showed that the former had better response performance for sensing Hg ion. The proposed method provides a simple tool for rapid, selective and sensitive monitoring of Hg ion in environmental samples.

Development of Novel and Highly Specific ssDNA-Aptamer-Based Electrochemical Biosensor for Rapid Detection of Mercury (II) and Lead (II) Ions in Water

“…A wide variety of aptamers offer both an additional and versatile way of providing the specific interactions required for biosensors. Recently, great progress has been made in the development of optical and electrochemical techniques for the detection of toxic metal ions using either artificial receptors, e.g., nanoparticles functionalised with DNAzymes [7], graphene oxide chemiresistor [8], or natural biological objects such as bacteria [9] and whole cells [10,11].…”

Practical Application of Aptamer-Based Biosensors in Detection of Low Molecular Weight Pollutants in Water Sources

“…Currently, many types of aptasensors were developed for detecting the Hg 2+ in water samples based on the different platforms, including electrochemistry, colorimetric and fluorescence-based analysis [ 73 , 74 , 75 ]. In addition, many signal amplification modes or novel platforms such as chemiluminescence (CL) [ 73 ], electrically rGO-based chemiresistor [ 69 ], silicon nanomaterials (SiNPs)-based fluorescence [ 70 ], fluorescence lateral flow strip [ 40 ] and exothermic chip [ 71 ] have also been developed for detecting the Hg 2+ in water samples. Among those, a simple and rapid CL aptasensor for Hg 2+ was developed in natural water samples with a limit of detection (LOD) of 16 pM within 30 min.…”

Fabrication of AO/LDH fluorescence composite and its detection of Hg2+ in water

“…Hg 2+ ion is one of the most prevalent forms of mercury species in environmental waters 2 , 3 , which can further transform into the more toxic methylmercury by microbial methylation 4 , 5 . Hg 2+ ion can accumulate in animal and human bodies through food chains 6 , with a high enrichment factor, and then affect the nerves, immune, and digestive systems and cause serious damage of kidney, liver, and brain 7 , 8 . Hence, there is a great need to develop a simple and rapid method for detection of trace Hg 2+ ion in water.…”

“…The traditional techniques for Hg 2+ ion detection include cold vapor atomic absorption spectrometry (CVAAS) 9 , 10 , inductively coupled plasma atomic emission spectrometry (ICPAES), atomic fluorescence spectrometry (AFS) 11 , liquid chromatography inductively coupled plasma mass spectrometry (LCICPMS) 12 , and anodic stripping voltammetry (ASV) 13 , 14 . Although these methods are reliable and sufficiently sensitive for routine analysis, there are several shortcomings, such as the need for expensive equipment, well-trained operators and complicated sample preparation, and not being competent for on-site detection in emergent pollution events 8 , 15 . Thus, a simple and rapid method to analyze Hg 2+ concentrations in water will be of great importance.…”