Evaluation of PLA-CB composite electrodes modified with poly(4-sulfonic acid-styrene-co-maleic acid) for the determination of dopamine

Composite electrodes consisting of poly(lactic acid) and carbon black (PLA-CB) had been describe as sensitive to various organic molecules and metal cations, presenting a certain degree of reproducibility and an excellent level of reliability.^[1] Such substrates can be modified by polymeric films^[2] leading to improvements in the analytical signals. In this work, the PLA-CB electrodes were modified with poly(4-sulfonic acid-styrene-co-maleic acid) (SSMAc) polymers by the drop casting technique for the detection of dopamine. SSMAc polymers were prepared from poly(styrene-co-maleic anhydride) (SMA), a synthetical polymer, by a sulfonation reaction. While applying the SSMAc polymers in the modification of the composite electrode, it was observed that the polymers act increasing sensitivity of the electrode, with the SSMAc polymer that had the highest content of sulfonic acid in the structure being the one that present the best results. In concentration range of 1 to 10 µmol L^-1 of dopamine, the modified electrode with the best modifier presented a LOD of 0.11 µmol L^-1, which is comparable to that available in the literature.

Agradecimentos. CNPq, CAPES, PPGQ-UFF

Referências. [1] V. N. Ataide, D. P. Rocha, A. de Siervo, T. R. L. C. Paixão, R. A. A. Muñoz, L. Angnes, Microchimica Acta 188 (2021).

[2] S. Jampasa, W. Khamcharoen, at al. Current Opinion in Electrochemistry 42 (2023).