Selective detection of nitenpyram by silica-supported carbon quantum dots

In this study, a fluorescent sensor of nitrogen-doped carbon quantum dots (N-CQDs) and silica gel hybrid was developed for the quantitative detection of nitenpyram, a toxic neonicotinoid existing in groundwater and/or surface water. The prepared N-CQDs@SiO2 sensor exhibited remarkable sensing selectivity and sensitivity towards nitenpyram among the four pesticides and six metal ions. A prominent fluorescence quenching of N-CQDs@SiO2 at 445 nm was observed in the presence of nitenpyram with a linear response range of 0–300.0 mg L−1 and an estimated limit of detection of 1.53 mg L−1. The main cause for selective sensing is that nitenpyram absorbs the excitation light of N-CQDs@SiO2, leading to fluorescence quenching of the sensor through the inner filter effect.