Detecting Mercury (II) and Thiocyanate Using “Turn-on” Fluorescence of Graphene Quantum Dots

• Published in: Journal of fluorescence Vol. 30; no. 5; pp. 1181 - 1187
• Main Authors: Askari, Faezeh, Rahdar, Abbas, Dashti, Mohadeseh, Trant, John F.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2020; Springer Nature B.V
• Subjects: Analytical Chemistry; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedicine; Biophysics; Biotechnology; Citric acid; Contaminants; Fluorescence; Fluorescent Dyes - chemical synthesis; Fluorescent Dyes - chemistry; Graphene; Graphite - chemistry; Heavy metals; Lead; Mercury (metal); Mercury - analysis; Original Article; Quantum dots; Quantum Dots - chemistry; Spectrometry, Fluorescence; Thiocyanates; Thiocyanates - analysis; fluorescent detection; Graphene quantum dot; Hg; SCN; Hg2
• ISSN: 1053-0509; 1573-4994
• DOI: 10.1007/s10895-020-02586-z

In this work, 1.8 nm graphene quantum dots (GQDs), exhibiting bright blue fluorescence, were prepared using a bottom-up synthesis from citric acid. The fluorescence of the GQDs could be almost completely quenched (about 96%) by adding Hg 2+ . Quenching was far less efficient with other similar heavy metals, Tl + , Pb 2+ and Bi 3+ . Fluorescence could be near quantitatively restored through the introduction of thiocyanate. This “turn-on” fluorescence can thus be used to detect both or either environmental and physiological contaminants mercury and thiocyanate and could prove useful for the development of simple point-of-care diagnostics in the future. Graphical Abstract