Tyrosinase-based ruthenium dispersed carbon paste biosensor for phenols.

Highly sensitive biosensors for phenolic compounds, based on the incorporation of the enzyme tyrosinase within metal-dispersed carbon paste matrices are described. In particular, ruthenium-doped carbon pastes display excellent electrocatalytic activity for the reduction of the enzymatically generated quinone species. Hence, convenient quantitation of micromolar concentrations is feasible at 0.0 V (vs. Ag/AgCl reference), with a greatly enhanced response compared to conventional carbon-paste tyrosinase biosensors. The influence of various experimental variables is explored. Fast, sensitive and reproducible flow injection detection of phenolic compounds is illustrated. Analogous improvements are reported for tyrosinase-rich plant tissue electrodes.