A novel molecularly imprinted nanosensor based on quartz crystal microbalance for specific recognition of α-amanitin

Abstract

α-Amanitin is the most toxic amanita identified in mushrooms, making early identification crucial for improving the human survival rates and preventing lethal poisoning cases. In this study, a novel molecular imprinting sensor based on quartz crystal microbalance (QCM) was developed for the determination of amatoxins in biological samples. To this end, allyl mercaptan was first used to attach polymerizable double bonds on the surface of QCM gold electrode. A molecularly imprinted polymer (MIP) coating was then deposited on the gold electrode surface using synthesized moieties of α-amanitin as templates and both 4-vinylpyridine and α-methacrylic acid as bi-functional monomers. The adsorption performances of the as-obtained quartz crystal microbalance molecular imprinting (QCM-MIP) sensor towards α-amatoxins were evaluated by a series of adsorption experiments. The as-prepared sensor displayed a good linear response towards α-amanitin from 1.0 ng/L to 50.0 ng/L. The sensor showed also low detection limit (0.052 pg/L), short response time (20 min), high adsorption capacity (138 μg/cm2), good reproducibility, and relevant stability. Furthermore, the as-obtained QCM-MIP sensor was successful in selective recognition of α-amanitin in biological samples with recoveries ranging from 80.6% to 103.8%. Overall, the proposed QCM-MIP looks useful for the construction of future selective and quick detection of α-amanitin in biological samples.