Highly sensitive detection of Cr(VI) by reduced graphene oxide chemiresistor and 1,4-dithiothreitol functionalized Au nanoparticles

Abstract

Detection of highly toxic Cr(VI) is greatly desired. In the present study, a highly sensitive method for Cr(VI) detection by reduced graphene oxide (rGO) chemiresistor and 1,4-dithiothreitol (DTT) functionalized Au nanoparticles (AuNPs) is reported. The detection strategy is based on the selective binding between DTT functionalized AuNPs1 located in rGO conductive channels and DTT functionalized AuNPs2 in solution through the formation of disulfides induced by Cr(VI) at acidic condition, which results in aggregation of DTT functionalized AuNPs2 on the rGO channels producing a readily measurable resistance change. The response of the chemiresistor is rapid and allows real-time monitoring of Cr(VI).Using this method, as low as 0.9 nM of Cr(VI) in water was detected with good selectivity.The proposed method has great potentials for monitoring of trace Cr(VI) in drinking water.

Ultrasensitive Colorimetric Chromium Chemosensor Based on Dye Color Switching under the Cr(VI)-Stimulated Au NPs Catalytic Activity

“…In addition, the LOD obtained by this chemosensor is much lower than the guidelines limit of 50 μg L –1 for Cr­(VI) regulated by the World Health Organization (WHO) in groundwater. The complicated environment in the practical Cr­(VI) detection, e.g., high acid or alkali and high saline, makes the chemosensor withstand more challenges. ,,, In our study, the paper-based chemosensor is employed for the detection of Cr­(VI) within pH 1–12, as shown in Figure S13. The results demonstrate that the paper-based chemosensor is hardly affected by pH, even in a high acid or alkali environment.…”

“…It responds to the particular analyte by converting the chemical stimuli into a signal that can be measured or recorded . In chemosensors, nanoparticles capped by different agents (e.g., citrate, 1,4-dithiothreitol, and thymine derivative) or molecules would present the aggregation and disaggregation or the chelation effect in the presence of a particular analyte, resulting in the color or fluorescence or UV–vis change. ,− Currently, chemosensors based on various innovative nanomaterials provide an alternative for Cr­(VI) detection; e.g., a Zr 4+ MOF was applied to selective sensing of Cr­(VI) with a detection limit of 0.004 mg L –1 . In a recent study, it was found that gallic acid-capped gold nanoparticles could be applied for colorimetric detection of Cr­(VI) via the aggregation-induced color change, with the limits of detection (LODs) being 2 μM by eye vision and 0.1 μM by UV–vis spectroscopy.…”

Recent Advances in Electrochemical Monitoring of Chromium

“…A chemiresistive sensor elaborated by the use of 1,4-dithiothreitol (DTT) functionalized AuNPs and reduced graphene oxide (rGO) was conducted for Cr(VI) determination [ 102 ]. The mechanism is based on the selective binding between the DTT functionalized AuNPs located in rGO conductive channels (DTT-AuNPs1) and DTT functionalized AuNPs in solution (DTT-AuNPs2) through the formation of disulfides bridges induced by Cr(VI) at acidic condition resulting in the aggregation of DTT-AuNPs2 on the surface of rGO channels which produces a measurable resistance change.…”

Nanomechanical Recognition and Discrimination of Volatile Molecules by Au Nanocages Deposited on Membrane-Type Surface Stress Sensors

“…It is common knowledge that the properties of AuNPs are strongly size- and shape-dependent, and they can be tuned through the well-established synthetic procedures and postsynthesis treatments. − However, to date, mostly spherical AuNPs have been applied in sensor devices, e.g ., as functional surface decoration in conventional metal oxides-based conductometric sensors, or organically modified AuNPs in chemiresistors . Some theoretical studies of AuNPs have been providing further insights into the electronic structure properties and charge transfer mechanism of such interesting systems. − More recently, some examples of nonspherical AuNP-based sensors have been demonstrated, such as urchin- and starlike gold nanoarchitectures applied in the microbalance weight detector and localized surface plasmon resonance sensors, respectively.…”