Highly sensitive fluorescent probe for mesotrione based on nitrogen and sulfur co-doped graphene quantum dots

Mesotrione is considered as an effective triketone herbicide for the control of major broadleaf grasses and some Gramineae weeds. However, over-application of mesotrione poses significant environmental and ecological hazards. The development of a mesotrione fluorescent sensor is essential for detecting mesotrione. A novel fluorescent probe (nitrogen and sulfur co-doped graphene quantum dots (N, S-GQDs)) was designed for the rapid analysis of mesotrione in real water samples. N, S-GQDs synthesized by pyrolytic carbonation have the multilayer graphene structure with the size range of 9.8–29.1 nm, the average size of 19.2 nm, and the average height of 9.7 nm. The fluorescent probe was capable of emitting high-intensity fluorescence. And when mesotrione was mixed with the fluorescent probe, the fluorescence of the probe was rapidly quenched by static quenching and the internal filter effect. The fluorescent probe provided great sensitivity and selectivity in the linear range of 0.5–15 and 15–700 μM for the detection of mesotrione with the detection limit (LOD) of 0.26 μM. Noticeably, real sample tests illustrated the use of the fluorescent probe for mesotrione was a promising strategy.