Polypyrrole film on miniaturized surface plasmon resonance sensor for ochratoxin A detection

Polypyrrole films doped with chloride (PPy-Cl) was formed, via electropolymerization of pyrrole at +0.76 V in 1 mM NaCl aqueous solution, on the gold surface of a miniaturized surface plasmon resonance (SPR) device for detecting ochratoxin A (OTA). By monitoring the SPR angle, the thickness of each PPy-Cl film could be controlled in situ from 2 to 5 nm. Binding interaction of these films with OTA followed a linear relationship between the rate of SPR angle increase and the OTA concentration from 0.1 to 10 mug/ml. The binding time was rapid (<5 min) and the required sample volume was small (0.2 ml). This OTA binding functionality of electropolymerized PPy films has been demonstrated via SPR measurement for the first time. (C) 2004 Elsevier B.V. All rights reserved.