Amperometric biosensors precision improvement. Application to phenolic pollutants determination

• Tyrosinase based sensor with improved precision was used for phenolic and triazine pollutants determination.
• Precision improvement was achieved by applying PAD to eliminate electrode fouling.
• Electrode fouling was characterized by cyclic voltammetry, amperometry, EQCM, and optical microscopy.
• RSD of 2.97% (0.6 mmol L−1 quinone, n=5) was achieved vs. 6.53% without the pulsed cleaning application.

Electrodes fouling associated with the electroenzymatic phenols determination was characterized in this work, applying various techniques such as cyclic voltammetry, amperometry, EQCM, and optical microscopy. An approach to overcome the fouling effects and hence to improve the precision of the phenolic compounds determination was suggested and tested. This approach consists of pulsed potential waveform application with a cleaning potential step of + 1.4 V vs. Ag, AgCl/KClsat with a duration of 166.66 ms, while the determination was carried out at 0.0 V vs. Ag, AgCl/KClsat applied for 66.64 ms. As a result a RSD of 2.97% for 0.6 mmol L−1 o-catechol determination was achieved, compared with 6.53% without the cleaning step application. The method was successfully used for the precise phenolic and triazine pollutants determination.

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