Stable and sensitive electrochemical detection of phenolic compounds at carbon nanotube modified glassy carbon electrodes

Carbon-nanotube modified glassy-carbon electrodes are used for enhancing the stability and sensitivity of voltammetric and amperometric measurements of phenolic compounds. Cyclic voltammetric experiments indicate that the redox process involves the formation of a surface-confined layer that promotes (rather than inhibits) the phenol oxidation. The amperometric response of the coated electrodes is highly stable, with 85% of the initial activity remaining after 30 min stirring of a 2 x 10(-4) M phenol solution (compared to complete inhibition of the redox process within 6 min at the bare surface). Similar stability improvements were observed for different phenolic compounds and different concentrations of such compounds. The modified electrodes display greatly enhanced current signals in cyclic voltammetric and amperometric experiments.