Selective and sensitive determination of cypermethrin in fish via enzyme-linked immunosorbent assay-like method based on molecularly imprinted artificial antibody-quantum dot optosensing materials

Molecularly imprinted silica layers appended to quantum dots (MIP-QDs) with customized selective artificial recognition sites were fabricated in this study by optimizing the ratio of the functional monomer to the template. Scanning electron microscopy, transmission electron microscopy, Brunaueremmett-teller, Fourier transform infrared spectroscopy, and selectivity assay analyses were also performed. Results demonstrated that the selective fluorescence quenching properties of MIP-QDs toward cypermethrin (CYP) are due to strong interactions between these molecules. An enzyme-linked immunosorbent assay (ELISA)-like method based on the MIP-QDs was established under optimal conditions. The fluorescence quenching observed from this method showed a linear relationship with CYP concentration over the range of 0.05-60.0 mg/kg with a correlation coefficient of 0.9838. Good recovery (82.7-92.4%) and a relative standard deviation of less than 10.1% were obtained from fish samples spiked with three levels of CYP. This method also demonstrated a low detection limit of 1.2 mu g/kg. The ELISA-like method based on MIP-QDs can be successfully employed to detect residual of CYP in fish samples. (C) 2015 Elsevier B.V. All rights reserved.