Leveraging an Innovative Green Copper and Nitrogen-Doped Carbon Quantum Dots for Quantification of Malathion in Various Matrices.

The efficiency of carbon quantum dots (CQDs) as a fluorescence probes has recently sparked considerable interest. Their cost-effectiveness, eco-friendly nature, water solubility, and unique photocatalytic properties have positioned them as distinctive alternatives to traditional luminescent techniques such as fluorescent dyes and luminous derivatization. In this study, green, stable, sustainable copper and nitrogen carbon dots (Cu-N@CQDs) were synthesized with a high quantum yield equal to 40.20% for analysis of malathion with various applications. Meanwhile, Malathion (MAL) is a widely used organophosphorus compound for insecticidal purposes, particularly in mosquito eradication and maintenance of public recreational spaces. The fluorescence intensity of the synthesized Cu-N@CQDs was quenched at 442 nm upon the gradual addition of MAL (excitation 360 nm). The calibration curve ranged from 1.0 to 90 ng mL, with a lower limit of quantitation (LOQ) of 0.94 ng mL and a lower limit of detection (LOD) of 0.43 ng mL. This proposed method was successfully applied for MAL determination in various matrices such as hair preparations, water, milk, and insecticide formulations, with a high recovery rate.