An amperometric biosensor for oganophosphorus (OP) pesticides based on a carbon-nanotube (CNT) modified transducer and an organophosphorus hydrolase (OPH) biocatalyst is described. A bilayer approach with the OPH layer atop of the CNT film was used for preparing the CNT/OPH biosensor. The CNT layer leads to a greatly improved anodic detection of the enzymatically-generated p-nitrophenol product, including higher sensitivity and stability. The sensor performance was optimized with respect to the surface modification and operating conditions. Under the optimal conditions the biosensor was used to measure as low as 0.15 ?M paraoxon and 0.8 ?M methyl parathion with sensitivities of 25 and 6 nA/µM, respectively.
Revised: November 22, 2005 |
Published: February 8, 2005
Citation
Deo R.P., J. Wang, I. Block, A. Mulchandani, K. Joshi, M. Trojanowicz, and F. Scholz, et al. 2005.Determination of Organophosphate Pesticides at a Carbon Nanotube/Organophosphorus Hydrolase Electrochemical Biosensor.Analytica Chimica Acta 530, no. 2:185-189.PNNL-SA-43263.