2, Instituto Tecnológico de Costa Rica, Cartago, , Costa Rica
3, Universidad de Costa Rica, San José, , Costa Rica
Conductive polymers are used in a variety of systems due to their electrochemical stability and inherent conductivity. Poly(3,4-ethylenedioxythiophene) (PEDOT) is synthesized through a micellar dispersion that allows the incorporation of biomolecules, which are useful in an wide range of applications, such as chemical detection, pharmaceutical, biomedical, and environmental. κ-carrageenan (κc) has been used for immobilization of microorganisms and as a biosurfactant. In this work, we have studied its doping effect in a conductive matrix. A PEDOT/κc system was obtained by electrodeposition, and its properties were compared to a standard surfactant, sodium dodecyl sulfate (SDS). The electrochemical characterization was performed to evaluate the stability and residual activity after polarization between -0.3 V and 0.9 V at a scan rate of 100 mV s-1 in aqueous solutions containing KClO4 as electrolyte. The oxidation level of the samples was studied using Raman Spectroscopy. It was shown that the reduced structure of PEDOT/SDS decreased after polarization, however the PEDOT/ κc system demonstrated a satisfactory behavior as doping agent during the analysis. Electrochemical activity remains constant after 150 cycles for the biopolymer system (PEDOT/κc) meanwhile it decreased for the standard PEDOT/SDS system. These results aim to use this conductive biopolymer system to incorporate biomolecules for multiple applications.