Internal light-driven efficient chemiluminescence of graphitic carbon nitride quantum dots for improved carboxin sensing

Developing a new chemiluminescence (CL) sensor platform to achieve the identification of pollutants in the water environment is a significant and currently hot topic for researchers. Building on the effective development of a CL internal light source, this paper designed a direct, simple, and rapid pesticide identification strategy. Specifically, graphite carbon nitride quantum dots (CNQDs) with excellent optical properties were synthesized using a solvent heat treatment strategy. Acting as an energy acceptor, CNQDs triggered CL emission in the presence of singlet oxygen (1O2). The newly developed CNQDs/1O2 CL sensor exhibited a specific response toward carboxin (CBX) with high sensitivity. Based on this discovery, we have developed a highly selective, ultra-sensitive, and fast CL sensing platform for detecting CBX in water environments. Through numerous experiments, we attributed the CL emission of the CNQDs/1O2 system to the specific chemiluminescent resonance energy transfer (CRET) process between CNQDs and 1O2. Interestingly, the CL light of the CNQDs/1O2 system could serve as an internal light source to excite CBX generating a large amount of 1O2 through photosensitization, which was crucial for further enhancing the CL efficiency of the CNQDs/1O2/CBX system and also enabled the CL sensing of CBX. This study is the first to successfully identify CBX in water using CL sensors, showcasing the potential of CL internal light sources in regulating CL efficiency and offering new perspectives on detecting pollutants in complex environments.