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⁻¹ and 0.05 ng mL⁻¹ to 100 ng mL⁻¹ and 25 ng mL⁻¹, respectively. For FB1, under 980-nm laser excitation, the logarithmic value of SERS signal intensity at 1567 cm⁻¹ gradually increases with the concentration of FB1 in the range 0.05–200 pg mL⁻¹ (R² = 0.996). The detection limits of the proposed assay for ZEN, OTA, and FB1 are 0.03 ng mL⁻¹, 0.01 ng mL⁻¹, and 0.02 pg mL⁻¹, 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.