Electrochemistry at cobalt(II)tetrasulfophthalocyanine-multi-walled carbon nanotubes modified glassy carbon electrode: a sensing platform for efficient suppression of ascorbic acid in the presence of epinephrine

• Published in: Journal of solid state electrochemistry Vol. 13; no. 9; pp. 1367 - 1379
• Main Authors: Agboola, Bolade O., Vilakazi, Sibulelo L., Ozoemena, Kenneth I.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2009
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Original Paper; Physical Chemistry; Epinephrine; Carbon nanotubes; Ascorbic acid
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-008-0691-3

Electrochemistry of water-soluble cobalt(II) tetrasulfophthalocyanine (CoTSPc) electrodeposited on glassy carbon nanotube pre-modified with acid-functionalized multi-walled carbon nanotubes (MWCNT) is described. Both charge transfer resistances toward [Fe(CN) 6 ] 3−/4− redox probe and electrocatalytic responses toward epinephrine (EP) detection follow the trend: bare GCE < GCE-MWCNT < GCE-CoTSPc < GCE-MWCNT-CoTSPc. EP analysis was then carried out in details using GCE-MWCNT-CoTSPc. The catalytic rate constant value k ch  = 2.2 × 10 7 (mol cm −3 ) −1 s −1 was obtained from rotating disk electrode experiment. Interestingly, GCE-MWCNT-CoTSPc efficiently suppressed the detection of ascorbic acid (the natural interference of neurotransmitters in physiological conditions) showing good sensitivity (0.132 ± 0.003 A l mol −1 ), limit of detection (4.517 × 10 −7 mol l −1 ), and quantification (15.056 × 10 −7  mol l −1 ). In addition, GCE-MWCNT-CoTSPc was conveniently used to determine EP in epinephrine hydrochloric acid injection with recovery of 101.1 ± 2.2%.