Aptamer fluorescence signal recovery screening for multiplex mycotoxins in cereal samples based on photonic crystal microsphere suspension array

- A novel aptamer photonic crystal microsphere (PHCM) suspension array for multiplex mycotoxins based on the aptamer fluorescence signal recovery was designed.
- The fluorescence signal could be restored by the mycotoxin targets binding their aptamer sequences labeled with Cy3.
- The four kinds of modification groups on the surfaces of PHCMs for aptamer immobilization were compared.
- The detection system presents an ultrasensitive, high selectivity and small volume reagents for multiplex mycotoxins with a wide linear detection range.

We design a novel high throughput photonic crystal microsphere (PHCM) suspension array for multiplex mycotoxins in cereal samples based on the aptamer fluorescence signal recovery. The hybridization duplex strand DNA from mycotoxin aptamer and anti-aptamer respectively labeled with fluorescence dye and quencher was immobilized on the carboxylated surfaces of PHCMs. When the corresponding mycotoxin targets bind to their aptamers, the fluorescence recovery signal intensity of PHCMs reported the concentration of mycotoxins. The different kinds of mycotoxins were distinguished by the structure colors of PHCMs. The fluorescence signal intensity on the PHCMs is nearly higher 100 times than that of solid glass beads. The detection system presents an ultrasensitive, high selectivity, and small volume reagent screening for multiplex mycotoxins with a dynamic linear detection range of 0.1 pg/mL-0.1 ng/mL for AFB1/OTA and 0.1 ng/mL-10 ng/mL for FB1 and a limit of detection (LOD) of 15.96 fg/mL, 3.96 fg/mL and 11.04 pg/mL for AFB1, OTA and FB1, respectively. The recovery rates in spiked cereal samples were well consistent with that of the traditional ELISA. The designed system provides a new high throughput aptamer-based suspension array for small molecule screening in parallel.