Toxicity evaluation of MC-LR in different fish organs based on aptamer-recognized SERS tag coupled with magnetic separation

Microcystin-LR (MC-LR) is a strong liver toxin, which will enter the human body by eating MC-LR-contaminated aquatic products. Therefore, it is urgent to explore whether people are exposed to MC-LR-contaminated aquatic products. Herein, a sensing strategy based on aptamer-recognized SERS tag coupled with magnetic separation was developed for ultrasensitive and specific detection of MC-LR in fish organs. This sensor had a dynamic range of 0.1 ng/L to100 µg/L and a limit of detection down to 0.1 ng/L for MC-LR. This ultrasensitive and rapid separation strategy allow us to explore the bioaccumulated amount of MC-LR in different fish organs. The results show that the order of MC-LR content accumulated in different organs of local crucian carps were heart > liver > kidney > meat > spleen. The MC-LR content in fish meat was 1.1–8.5 times of the WHO proposed tolerable daily intake level (TDI), implying the aquatic products in local aquatic market had potential threats to human health.