Electrochemical sensors are devices capable of collecting data with minimal manipulation of the system, with some drawbacks like surface poisoning and high over voltages to oxidize (or reduce) the analytes. It is possible to immobilize chemical species on the electrode surface in order to increase its sensitivity and selectivity in the detection of molecules of biological importance, such as Uric Acid (UA). UA is a biomolecule produced by the catabolism of purines that when found in high concentrations in the body indicates the clinical disorder known as Gota. A system of three electrodes in a glass cell (5 mL) was used: chemically modified Glassy Carbon Electrode (GCE), auxiliary electrode (platinum wire) and reference electrode (Ag/AgCl). Capsaicin was polymerized on GCE/MWCNT being important as redox mediator for electroanalysis of uric acid in blood plasma.