Microplasma-Enabled Sustainable Synthesis of Nitrogen-Doped Graphene Quantum Dots for Sensitive Detection of 4-Nitrophenol

Abstract

4-nitrophenol (4-NP) is one of the organic pollutants that can come up from pesticides, explosives, dyes, and pharmaceutical industries. Since it can be extremely harmful to humans and other living organisms, it is crucial to have a system that can effectively detect the presence of 4-NP. Here, we report the microplasma synthesis of nitrogen-doped graphene quantum dots (N-GQDs) for fluorescence-based detection of 4-NP. Through Förster resonance energy transfer (FRET) between donor N-GQDs to the acceptor 4-NP, synthesized N-GQDs can be employed for the detection of 4-NP starting from 0.5 to 100 µM with a limit of detection as low as 95.14 nM. 4-NP detection also demonstrates remarkable stability over all pH values and wide temperatures (10–60 °C), indicating the high possibility for robust organic pollution monitoring. Our work provides insight into a simple, fast, and environmentally friendly method for synthesizing N-GQDs at ambient conditions usable for environmental nanosensors.