Selective detection of carbendazim using a upconversion fluorescence sensor modified by biomimetic molecularly imprinted polymers

The persistence of carbendazim residues in the food chain poses a potential risk to human health. Therefore, an eco-friendly selective and sensitive fluorescence nanosensor was established for carbendazim determination based on molecularly imprinted polymer (MIP) modified upconversion nanoparticles (UCNPs). The molecularly imprinted coating with methacrylamide as a functional monomer and carbendazim as a template molecule grafted on the UCNPs (UCNPs@MIP) constituted fluorescent recognition elements. The fluorescence emission of UCNPs@MIP significantly declined in the presence of carbendazim due to electron transfer induced by its selective binding with MIP cavities. The quenched fluorescence of UCNPs@MIP was recovered once the template carbendazim was eluted from the probe system. Under the optimized conditions, the proposed method offers a good linear correlation between 0.01 and 1 mu g/mL, with a limit of detection (LOD) of 0.0036 mu g/mL for carbendazim residues. The analytical utility and reliability of the developed biomimetic platform were examined in real food samples with good recoveries (88.790%similar to 102.675%) and relative standard deviation (RSD) values (0.491%similar to 3.779%). The method was further validated by a standard HPLC method in terms of student's t-test (p > 0.05) with no significant differences between the two methods. Hence, the proposed fluorescence sensor has prospects for rapid determination of carbendazim.

Automated summary

A fluorescence nanosensor based on molecularly imprinted polymer modified upconversion nanoparticles was established for the selective and sensitive determination of carbendazim residues. The method showed good linearity, sensitivity, and stability in real food samples.