Rapid microwave-assisted green synthesis of guanine-derived carbon dots for highly selective detection of Ag+ in aqueous solution

In this work, a simple and green synthetic approach of novel guanine decorated carbon dots (G-CDs) using guanosine 50-monophosphate and ethylenediamine through a domestic microwave oven was established for the first time. The as-prepared fluorescent G-CDs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis spectroscopy, and fluorescence spectroscopy. The obtained fluorescent G-CDs with a uniform morphology had desirable functional groups and excellent optical performances. Furthermore, the fluorescence intensity of G-CDs was remarkably quenched by Ag+ than that of other nucleotides-derived CDs. The density functional theory calculations were performed to confirm that the strong interaction of guanine-Ag+ was responsible for the remarkable fluorescence response of G-CDs towards Ag+. In addition, as a label-free fluorescence probe, the G-CDs displayed a good linear detection for highly selective Ag+ sensing over the range of 0-80 lM with the low detection limit of 90 nM. Therefore, the proposed G-CDs had the capacity for Ag+ detection in the real samples. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A simple and green synthetic approach of guanine decorated carbon dots (G-CDs) using a domestic microwave oven was established for the first time. The obtained G-CDs showed remarkable fluorescence response towards Ag+ with good linear detection and low detection limit. Density functional theory calculations confirmed the strong interaction of guanine-Ag+ responsible for the fluorescence response of G-CDs towards Ag+.