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VISCOSITY AND BINDER COMPOSITION EFFECTS ON TYROSINASE-BASED CARBON PASTE ELECTRODE FOR DETECTION OF PHENOL AND CATECHOL
Citation:
Rogers, K R., J. Y. Becker, J Cembrano, AND S H. Chough. VISCOSITY AND BINDER COMPOSITION EFFECTS ON TYROSINASE-BASED CARBON PASTE ELECTRODE FOR DETECTION OF PHENOL AND CATECHOL. TALANTA 54(6):1059-1065, (2001).
Impact/Purpose:
The overall objective of this task is to develop scientifically sound sampling and bioanalytical approaches for screening and monitoring of hazardous wastes. These techniques are expected to provide the Agency with improved screening and field portable methods to characterize, reduce, and control risk to human health and the environment. Specific objectives will include development and characterization of the following concepts:
SPMDs for passive accumulation of TICs
Bioassays for toxic and genotoxic compounds
MIPs for volatile and semivolatile toxic organics
Rapid screening assays using the previously listed components.
Description:
The systematic study of the effect of binder viscosity on the sensitivity of a tyrosinase-based carbon paste electrode (CPE) biosensor for phenol and catechol is reported. Silicon oil binders with similar (polydimethylsiloxane) chemical composition were used to represent a wide range of viscosities (10 to 60,000 mPa.s at 25 C) while minimizing polarity effects. The highest response for both phenol and catechol was achieved using a silicon oil binder of intermediate viscosity (100 mPa.s). The binder viscosity showed no appreciable effect on the direct oxidation of phenol and catechol using a plain CPE, suggesting the involvement of diffusion kinetics in the binder matrix for the enzyme-based CPE. The effect of the relative binder concentration in the carbon paste was measured over the range of 30-70%. Optimal results were obtained using 40% silicon oil. For comparison of the viscosity effects observed with the carbon paste electrode (CPE) containing silicon oil, other low and high viscosity mineral oils and paraffin waxes were also examined.
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), funded this research. It has been subject to the EPA's peer and administrative review and has been approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation by EPA for use.