Aptasensing a class of small molecules based on split aptamers and hybridization chain reaction-assisted AuNPs nanozyme.

Constructing robust group-specific probes and non-competitive analysis methods for small molecules in the fields of food analysis is of great significance. In this study, three diarrhetic shellfish poisons (DSPs) with high safety risks to humans were taken as models of group targets, and a non-competitive and turn-on format colorimetric aptasensor was constructed for simultaneous and highly sensitive detection of the class of DSPs. A pair of anti-DSP split aptamers were generated with group-specific binding affinity to the three targets. The split aptamers were then fabricated with a hybridization chain reaction (HCR)-enhanced AuNPs nanozyme. The aptasensor realized linear detection range of 187.5-3000 pM, high sensitivity with a limit of detection (LOD) as low as 65.36 pM, good selectivity, as well as good accuracy when analyzing the DSPs in shellfish samples. This study provides good reference for developing robust probes and facile biosensors to detect multiple small molecules in food matrix.