Dual-signal ratiometric electrochemical aptasensor for Zearalenone detection based on magnetic-assisted enrichment and hybridization chain reaction.

In this work, a dual-signal ratiometric electrochemical aptasensor based on the hybrid chain reaction (HCR) and streptavidin-modified magnetic beads (SA-MBs) was developed to rapidly detect zearalenone (ZEN). The HCR, as a powerful signal amplification technique to imporve the signal of sonser. When the target is present, they specifically bind with ZEN-Apt and release ZEN-cDNA to trigger HCR. Simultaneously, more double-stranded DNA causes the signal of Thi to be blocked. As a result, the two signals tend to change in the opposite direction as the ZEN concentration changes. Additionally, the peak current ratio of I/I showed a positive correlation with the ZEN concentration. Under optimal conditions, the constructed biosensor showed an excellent linear detection range (1.0 × 10 mol/L to 1.0 × 10 mol/L), a low detection limit (4.4 × 10 mol/L) and high specificity for ZEN. In addition, the detection method retains the characteristics of low cost and rapid detection of electrochemical detection, while improving the detection limit and detection accuracy via SA-MBs and internal reference signal. This provides a new idea for the practical detection of ZEN.