An aptamer based surface plasmon resonance biosensor for the detection of ochratoxin A in wine and peanut oil

Ochratoxin A (OTA), as a kind of chlorophenolic mycotoxin, exist widely in plant origin food and is

harmful to human. Herein, a surface pla**on resonance (SPR) biosensor using an anti-OTA aptamer

immobilized sensor chip was developed to measure ochratoxin A (OTA) quantificationally through a

straightforward direct binding assay. The streptavidin protein as a crosslinker was immobilized onto the

surface of a sensor chip and the biotin-aptamer was captured through streptavidin-biotin interaction.

The biosensor exhibited a detection range from 0.094 to 100 ng/mL (linear range from 0.094 to 10 ng/mL)

of OTA with a lower detection limit of 0.005 ng/mL. Detection of OTA in wine and peanut oil was further

performed in the SPR biosensor using simple liquid–liquid extraction for sample pretreatments. Recoveries of ochratoxin A from spiked samples ranged from 86.9% to 116.5% and coefficients of variation

(CVs) ranged from 0.2% to 6.9%. The developed methods in our studies showed good ****ytical performances with limits of detection much lower than the maximum residue limit, as well as a good reproducibility and stability.