Highly selective fluorescence probe for imidacloprid measurement based on fluorescence resonance energy transfer

Abstract

Herein, a fluorescent probe was investigated for the detection of imidacloprid based on the fluorescence resonance energy transfer (FRET) between two carbon-based quantum dots, namely graphene- and carbon quantum dots (GQDs/C-dots). In an HAc-NaAc buffer solution at pH = 5.0, an effective FRET occurred between the GQDs and C-dots, significantly enhancing the C-dot fluorescence. When imidacloprid was added to the FRET system, the fluorescence intensity of the C-dots was quenched in a linear imidacloprid concentration-dependent manner, which allowed for the establishment of a new method for the determination of imidacloprid by GQD/C-dot FRET. Under optimised experimental conditions, the linear range of imidacloprid was 5–4000 × 10⁻⁹ mol L⁻¹, with a correlation coefficient r and a detection limit of 0.998 and 8.23 × 10⁻¹⁰ mol L⁻¹, respectively. This method was applied to the detection of imidacloprid residues in real samples, and a satisfactory recovery rate of standard additions was found between 93.0% and 105.6%.