Aptamer-based microcantilever-array biosensor for ultra-sensitive and rapid detection of okadaic acid

Okadaic acid (OA) is widely present in seafood and consuming OA contaminated seafood can cause carcinogenic or teratogenic effects. Therefore, developing ultra-sensitive and rapid detection methods for OA is crucial. Here, an aptamer-based microcantilever array sensor was developed for ultra-sensitive and rapid detection of OA. OA aptamers were immobilized on a microcantilever through a thiol group in one step, thus greatly simplifying cumbersome preprocessing procedures. The detection limit of this assay for OA is 1 pg mL(-1), the lowest of reported aptamer-based OA detection method. More importantly, compared with reported methods, our method based on micro-cantilever array sensor has the advantages of being rapid, label-free, economical and more applicable for food sample detection. We proposed a method of using enzyme-catalyzed amplification on microcantilever arrays and then used this method to verify the successful modification of aptamers. The sensor also showed the applicability in food sample detection and specificity to OA in shellfish toxin. Therefore, our results prove that this highly sensitive assay based on microcantilever sensor has practical application prospect in assessment in the quality and toxicity monitoring of seafood.