L-cysteine functionalized graphene quantum dots for sub-ppb detection of As (III)

Abstract

Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry, and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III).

Advances in Nanomaterials and Colorimetric Detection of Arsenic in Water: Review and Future Perspectives

“…The study detailed in the research paper demonstrated that the optical response of GQDs rapidly changed upon contact with As(III) across a concentration range from 0.025 to 25 ppb, encompassing the permissible limit of arsenic in drinking water. These findings highlight the excellent sensitivity and selectivity of L-cysteine functionalized GQDs for detecting As(III), showcasing their potential for environmental monitoring applications [ 66 ].…”

Advances in the ratiometric combination of quantum dots for their use in sensing applications

“…Since it creates a strong sulfur-arsenic bond, the thiol component of these compounds is a well-known binder with arsenic. 80 Mercaptosuccinic acid 110 and l -cysteine 111 were also employed for the detection of arsenic in the aqueous medium in other references. Here, two quantum dot systems were represented by the work.…”