Building heterogeneous core-satellite chiral assemblies for ultrasensitive toxin detection

A chiral-aptasensor for ochratoxin A (OTA) detection based on Au core-Ag nanoparticle satellite assemblies was fabricated for the first time. High yields of Au core-Ag NP satellite assemblies were prepared in the aqueous phase and the optical properties of the Au core-Ag NP satellite assemblies were investigated in detail. Because of the different concentrations of the OTA target, the assembly degree of the architecture varied which led to the corresponding chiral signals. The developed method for OTA detection with excellent linear range from 1 to 50 pg/mL showed high selectivity for OTA and the limit of detection as low as 0.16 pg/mL. The feasibility of this method was demonstrated by performing recovery experiment using negative red wine samples, excellent recovery ranged from 90% to 105% was achieved, and indicated promising applications.