Interaction of ochratoxin A with molecularly imprinted polypyrrole film on surface plasmon resonance sensor

A molecularly imprinted polypyrrole (MIPPy) film was synthesized on the Spreeta sensor, a miniaturized surface plasmon resonance device, for detection of ochratoxin A (OTA). The MIPPy was electrochemically polymerized on the sensor surface from a solution of pyrrole and OTA in ethanol/water (1:9 v/v). The film growth was monitored in situ by an increasing SPR angle. Binding properties of the MIPPy film were investigated by loading OTA standard solutions into the integrated 20-μL flow cell. After 300 s, nonlinear regression was used to determine the maximum binding signal (Δ300). Spreeta results showed that Δ300 was measurable for OTA concentrations down to 0.05 ppm. By pulsed elution, 1% acetic acid in methanol/water (1:9 v/v) was found to be efficient for regeneration of the MIPPy film surface. Interference by the matrices of wheat and wine extracts was evaluated. No significant binding of the wheat extract with MIPPy was observed when acetonitrile/water (1:1 v/v) was used as the mobile phase.