Redox polymer covalently modified multiwalled carbon nanotube based sensors for sensitive acetaminophen and ascorbic acid detection

Nathaniel Havens, Phong Trihn, Daniel Kim, Manelich Luna, Adam K. Wanekaya, Amos Mugweru

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

A sensitive electrochemical detection method was developed involving multiwalled carbon nanotubes (MWCNTs) covalently modified with osmium-based redox polymer. The polycationic redox polymer, poly[4-vinylpyridine Os(bipyridine)2Cl]-co-ethylamine (POs-EA), was first synthesized and covalently attached to MWCNTs. The redox polymer modified MWCNTs were then trapped in a hydrogel formed from polyethyleneglycol diacrylate (PEG-DA) using 1-phenyl-2-hydroxy-2-methyl-1-propanone as a photoinitiator. Upon exposure to aqueous media, the gel swelled to allow movement of analytes in and out of the gel without having any effect on the redox polymer modified nanotube signal. Cyclic voltammetry showed reversible pairs of oxidation-reduction peaks at 0.35 V (vs Ag/AgCl) corresponding to the OsII/OsIII. This assembly was able to catalytically oxidize both acetaminophen and ascorbic acid (AA). Amperometric data showed a linearity between 0 and 100 μM (R2 of 0.999, n = 10) 0.5 mV vs Ag/AgCl (sensitivity 0.003 μA/μM) for ascorbic acid, while for acetaminophen the linearity was between 0 and 1.5 μM (R2 of 0.9999, n = 8) with a sensitivity of 65 μA/μM. This sensing system was found to exhibit remarkable stability over several weeks with excellent reproducibility.

Original languageEnglish (US)
Pages (from-to)2186-2190
Number of pages5
JournalElectrochimica Acta
Volume55
Issue number6
DOIs
StatePublished - Feb 15 2010

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Electrochemistry

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