Graphene oxide-fluorescent aptasensor for simultaneous detection of diarrhetic shellfish toxins: A comparison of parental aptamer with split aptamers

The efficient and simultaneous detection of diarrhetic shellfish toxins (DSTs) is of tremendous importance to marine food safety. Utilizing graphene oxide (GO) as fluorescence conversion component and fluorescence on and off as recognition indicators, two types of GO-fluorescent aptasensor (i.e., parental aptamer-based aptasensor and split aptamers-based aptasensor), mainly focusing on comparing their performance in the simultaneous detection of three DSTs, were proposed in this study. The results revealed that the split aptamers-based aptasensor displayed a lower limit of detection (0.0749 ng/mL) in a linear range of 0.1 ng/mL ∼ 1.0 μg/mL. By comparison, the limit of detection of the parental aptamer-based aptasensor was only 0.1366 ng/mL. Both types of aptasensors had good specificity and anti-interference performance, and exhibited good accuracy in analyzing DSTs in natural shellfish samples. This study provides good reference for developing simple, rapid, efficient, and low-cost biosensors for simultaneous detection of various small molecules in food matrices.