Thermally induced electrode protection against biofouling.

This paper demonstrates that a combined thermal and electrochemical conditioning step can greatly minimize electrode blocking. We detected 50 ppm dopamine after a blocking step in 1000 ppm gelatine solution. Only a treatment of the electrode at -1.5 V and 61.5 degrees C can reveal the voltammetric dopamine signals to 82%. The increase of the peak separation of the cyclic voltammograms obtained in 50 ppm dopamine is limited to 14%, whereas negative polarization (-1.5 V) alone leads to a 31% increase compared to 109% upon thermal and 105% without any conditioning. The positive effects can be addressed to an enforced reductive degradation and accelerated removal of the blocking agents. Also the formation of hydrogen bubbles might play a significant role. Thermo-electrochemical treatment holds great promise for electrochemical sensors and detectors which are applied for long-term monitoring of samples that contain blocking matrices.