In this work, a simple and green synthetic approach of novel guanine decorated carbon dots (G-CDs) using guanosine 5'-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 μM with the low detection limit of 90 nM. Therefore, the proposed G-CDs had the capacity for Ag⁺ detection in the real samples.

在这项工作中，首次建立了通过鸟嘌呤5'-单磷酸酯和乙二胺通过家用微波炉的新型鸟嘌呤修饰的碳点（G-CD）的简单绿色合成方法。制备的荧光G-CD通过透射电子显微镜，X射线光电子能谱，紫外可见光谱和荧光光谱来表征。所获得的具有均匀形态的荧光G-CD具有期望的官能团和优异的光学性能。此外，与其他核苷酸衍生的CD相比，G + CD的荧光强度被Ag ⁺显着淬灭。进行密度泛函理论计算以确认鸟嘌呤-Ag ⁺的强相互作用导致了G-CD对Ag ⁺的显着荧光响应。此外，作为一种无标记的荧光探针，G-CD对0-80μM范围内的高选择性Ag ⁺感测具有良好的线性检测，检测限为90 nM。因此，建议的G-CD具有在实际样品中检测Ag ⁺的能力。