Development and application of a novel fluorescent nanosensor based on FeSe quantum dots embedded silica molecularly imprinted polymer for the rapid optosensing of cyfluthrin

•Specific MIP-FeSe-QDs based on FeSe-QDs with selective FL quenching to CYF was developed.•The selective fluorescence quenching mechanism of MIP-FeSe-QDs were elucidated.•The optosensing sensor method for sensitive detection of CYF in fish and sediment were developed.

A novel molecularly imprinted silica layer appended to FeSe quantum dots (MIP-FeSe-QDs) was fabricated and utilized as a recognition element to develop a selective and sensitive fluorescent nanosensor for cyfluthrin (CYF) determination. The MIP-FeSe-QDs were characterized by fluorescence spectrometry, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Excellent selectivity and high sensitivity of MIP-FeSe-QDs to CYF molecules were observed based on the fluorescence quenching of FeSe-QDs. Under optimal conditions, a good linear relationship was found between fluorescence quenching effect and increased CYF concentration within 0.010-0.20 mg/L, with a correlation coefficient of 0.9911. The practicality of the developed sensor method for CYF detection in fish and sediment samples was further validated. Good recoveries ranging from 88.0% to 113.9% with<6.8% relative standard deviations were obtained. The detection limits of CYF in sediment and fish samples were 1.3 and 1.0 µg/kg, respectively. This study established a novel, rapid fluorescent nanosensor detection method based on MIP-QDs for successfully analyzing CYF in fish and sediment samples.