Preparation and electrochemical characterization of a carbon ceramic electrode modified with ferrocenecarboxylic acid.
The present paper describes the characterization of a carbon ceramic electrode modified with ferrocenecarboxylic acid (designated as CCE/Fc) by electrochemical techniques and its detection ability for dopamine. From cyclic voltammetric experiments, it was observed that the CCE/Fc presented a redox pair at E(pa) = 405 mV and E(pc) = 335 mV (ΔE = 70 mV), related to the ferrocene/ferrocenium process. Studies showed a considerably increase in the redox currents at the same oxidation potential of ferrocene (E(pa) = 414 mV vs. Ag/AgCl) in the presence of dopamine (DA), differently from those observed when using only the unmodified CCE, in which the anodic peak increase was considerably lower. From SWV experiments, it was observed that the AA (ascorbic acid) oxidation at CCE/Fc occurred in a different potential than the DA oxidation (with a peak separation of approximately 200 mV). Moreover, CCE/Fc did not respond to different AA concentrations, indicating that it is possible to determine DA without the AA interference with this electrode.
Department of Chemistry, Universidade Estadual Ponta Grossa, Avenida Carlos Cavalcanti 4748, Uvaranas, Ponta Grossa, Brazil. tatiuepg@hotmail.com
Tatiane
T
Skeika
Cristiane R
CR
Zuconelli
Sergio T
ST
Fujiwara
Christiana A
CA
Pessoa
D001205:Ascorbic Acid / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D004298:Dopamine / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004573:Electrolytes; D005296:Ferrous Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D000075163:Metallocenes; D008855:Microscopy, Electron, Scanning; D013052:Spectrometry, X-Ray Emission
D004573:Electrolytes; D005296:Ferrous Compounds; D000075163:Metallocenes; C032949:ferrocenecarboxylic acid; D002244:Carbon; D001205:Ascorbic Acid; D004298:Dopamine