Fabrication of L-Cysteine functionalized Graphene quantum dots as a fluorescent nanosensing probe for determination of mercury. Issue 1 (March 2020)

• Record Type: Journal Article
• Authors: Dewangan, Pradeep Kumar; Khan, Fahmida; Sahu, Vinayak; kashyap, Komal; Chandra, Ch; Patel, Khilawan
• Is Part Of: IOP conference series. Volume 798:Issue 1(2020)
• Publication Date: 2020-03
• Subjects: Fluorescence probe -- Cysteine -- Mercury ion -- Graphene quantum dots -- pyrolysis; Materials science -- Periodicals; 620.1105
• DOI: 10.1088/1757-899X/798/1/012030
• Languages: English
• ISSNs: 1757-8981

Abstract

Abstract: A highly sensitive and selective nanosensing probe for mercury ion is reported. Herein highly luminescent cysteine(cys) functionalized Graphene quantum dots(GQDs) were fabricated through facile one-step pyrolysis method by using ethylene glycol and cysteine. The coating of cysteine not only increases quantum yield to 41% but also enhances selective detection of ppb level of mercury ion in the waste water. The fluorescence intensity of Cys-GQDs was sequentially quenched by different concentrations of mercury ion via forming non-luminescent complexes of Cys-GQDs-Hg(II). HR-TEM study clearly shows a monodisperse Cys-GQDs of sizes 2-5 nm with a spherical shape. Raman spectra of Cys-GQDs display the D and G bands at 1350 cm −1 and 1580 cm −1 respectively. Optimum pH is 8 for mercury detection. The minimum limit for accurate detection of mercury is 0.64 ppb