Piezoelectric aptasensor with gold nanoparticle amplification for the label-free detection of okadaic acid

Okadaic acid (OA) is one of the most common marine biological toxins, which can cause human poisoning or even death. It is desirable and essential to develop novel approaches for OA detection in a convenient, practical and low-cost manner. In this study, a novel piezoelectric aptasensor was designed for the detection of OA. The aptamers specifically binding with OA were used as the sensing elements. Quartz crystal microbalance (QCM) device was used as the transducer for responsive signal detection. Gold nanoparticles (AuNPs) were used to amplify the detection signals. The results showed that the linear detection range of OA was 0.5 ∼ 200 nM with a detection limit of 0.32 nM. This biosensor provides a novel approach for inexpensive, ultrasensitive, well-specific and label-free detection of OA as well as other marine biological toxins with minor modifications.