Pristine multi-walled carbon nanotubes/SDS modified carbon paste electrode as an amperometric sensor for epinephrine.
An amperometric sensor for the determination of epinephrine (EP) was fabricated by modifying the carbon paste electrode (CPE) with pristine multi-walled carbon nanotubes (pMWCNTs) using bulk modification followed by drop casting of sodium dodecyl sulfate (SDS) onto the surface for its optimal potential application. The modified electrode showed an excellent electrocatalytic activity towards EP by decreasing the overpotential and greatly enhancing the current sensitivity. FE-SEM images confirmed the dispersion of pMWCNTs in the CPE matrix. EDX analysis ensured the surface coverage of SDS. A comparative study of pMWCNTs with those of oxidized MWCNTs (MWCNTsOX) modified electrodes reveals that the former is the best base material for the construction of the sensor with advantages of lower oxidation overpotential and the least background current. The performance of the modified electrode was impressive in terms of the least charge transfer resistance (Rct), highest values for diffusion coefficient (DEP) and standard heterogeneous electron transfer rate constant (k°). Analytical characterization of the modified electrode exhibited two linear dynamic ranges from 1.0×10(-7) to 1.0×10(-6)M and 1.0×10(-6) to 1.0×10(-4)M with a detection limit of (4.5±0.18)×10(-8)M. A 100-fold excess of serotonin, acetaminophen, folic acid, uric acid, tryptophan, tyrosine and cysteine, 10-fold excess of ascorbic acid and twofold excess of dopamine do not interfere in the quantification of EP at this electrode. The analytical applications of the modified electrode were demonstrated by determining EP in spiked blood serum and adrenaline tartrate injection. The modified electrode involves a simple fabrication procedure, minimum usage of the modifier, quick response, excellent stability, reproducibility and anti-fouling effects.
Electrochemistry Research Group, Department of Chemistry, St. Joseph׳s College, Lalbagh Road, Bangalore 560027, Karnataka, India.
Tony
T
Thomas
Electrochemistry Research Group, Department of Chemistry, St. Joseph׳s College, Lalbagh Road, Bangalore 560027, Karnataka, India. Electronic address: ronaldmasc2311@yahoo.co.in.
Ronald J
RJ
Mascarenhas
Electrochemistry Research Group, Department of Chemistry, St. Joseph׳s College, Lalbagh Road, Bangalore 560027, Karnataka, India.
Ozma J
OJ
D' Souza
Laboratoire de Chimie et d׳Electrochimie des Surface, University of Namur, 61 Rue de Bruxelles, B-5000 Namur, Belgium.
Simon
S
Detriche
Laboratoire de Chimie et d׳Electrochimie des Surface, University of Namur, 61 Rue de Bruxelles, B-5000 Namur, Belgium.
Zineb
Z
Mekhalif
Electrochemistry Research Group, Department of Chemistry, St. Joseph׳s College, Lalbagh Road, Bangalore 560027, Karnataka, India.
Praveen
P
Martis
D015374:Biosensing Techniques / Q000295:instrumentation; D001774:Blood Chemical Analysis; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D058266:Dielectric Spectroscopy; D004563:Electrochemistry; D004566:Electrodes; D004837:Epinephrine / Q000032:analysis* / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D015203:Reproducibility of Results; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry
D037742:Nanotubes, Carbon; D012967:Sodium Dodecyl Sulfate; D002244:Carbon; D010100:Oxygen; D004837:Epinephrine
Diffusion coefficient; Epinephrine; Modified carbon paste electrode; Multi-walled carbon nanotubes; Sodium dodecyl sulfate