Electroanalytical determination of catechol by a biosensor based on laccase from Aspergillus oryzae immobilized on gold screen-printed electrodes

In the present work, the detection of catechol (CC) was studied by using a biosensor of gold screen-printed electrode functionalized with laccase and cysteine as a linker. Cyclic voltammetry (CVs) studies were performed in order to determine the stability range of the biosensor and the redox processes present on the surface of the modified screen-printed gold electrodes (SPGE). CVs studies showed a variation in the response of the electrodes, finding one oxidation signal at 400 mV in presence of catechol, corresponding to the bio-electrocatalytic oxidation of catechol. The chronoamperometric response of the sensor to different concentration of catechol was measured applying 500 mV, obtaining a linear response of the current in function of the catechol concentration. The linear range of the detection was 0.02 - 2.4 mM, with a sensibility of 3.93 mu A mu M-1 cm(-2) and a detection limit of 1.2 mu M with a response time lower than 5 s. The results obtained in this work open new possibilities for the development of portable electrochemical biosensors for quick and efficient detection of catechol in industrial wastewater.