Trimer-based aptasensor for simultaneous determination of multiple mycotoxins using SERS and fluorimetry.

An aptasensor is reported for the detection of three different kinds of mycotoxins, i.e., zearalenone (ZEN), ochratoxin A (OTA), and fumonisin B1 (FB1). Based on fluorescence resonance energy transfer effect (FRET) and surface-enhanced Raman scattering (SERS), the levels of ZEN, FB1, and OTA can be simultaneously determined. Under 980-nm and 650-nm laser excitation, the logarithmic values of fluorescence signal intensities at 543 nm and 670 nm are slowly increased as the concentrations of ZEN and OTA vary from 0.1 ng mL and 0.05 ng mL to 100 ng mL and 25 ng mL, respectively. For FB1, under 980-nm laser excitation, the logarithmic value of SERS signal intensity at 1567 cm gradually increases with the concentration of FB1 in the range 0.05-200 pg mL (R = 0.996). The detection limits of the proposed assay for ZEN, OTA, and FB1 are 0.03 ng mL, 0.01 ng mL, and 0.02 pg mL, respectively. The selectivity experiment results indicate this assay possesses a high selectivity over other commonly encountered mycotoxins. The average recoveries range from 90 to 107%, revealing satisfactory application potential of the proposed assay. The developed aptasensor will bring bright prospects for research in the field of multiplexed mycotoxine detection. Graphical Abstract Schematic representation of an aptamer-based assay for multiple mycotoxins determination.