Electrospun iridium oxide nanofibers for direct selective electrochemical detection of ascorbic acid

Su Jin Kim, Yu Lim Kim, Areum Yu, Jiyoung Lee, Sang Cheol Lee, Chongmok Lee, Myung Hwa Kim, Youngmi Lee

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

We report the electrochemical activity of IrOx (0 < x ≤ 2) nanofibers prepared by electrospinning for the oxidations of biological species including L-ascorbic acid (AA), 4-acetamidophenol (AP), dopamine (DA), glucose, β-nicotinamide adenine dinucleotide (NADH), and uric acid (UA). Compared to bare glassy carbon electrode, IrOx nanofibers show high electroactivity for all the tested species and facilitate AA oxidation most significantly, shifting the oxidation potential to the less positive direction by ∼485 mV in linear sweep voltammetry while the oxidation of glucose is almost negligible at both electrodes. The amperometric response of IrO x nanofibers at the applied potential of -0.01 V (vs. SCE) is linearly proportional to the AA concentration, exhibiting high sensitivity (194.4 ± 6.8 μA mM-1 cm-2, n = 5), fast response time (t95% = 2.9 ± 1.2 s, n = 5), low detection limit (<0.4 μM), and exclusive selectivity over AP, DA, glucose, NADH, and UA at their physiological levels. In addition, excellent potential resolution of IrO2 nanofibers, sufficient to differentiate AA, DA, NADH, and UA, is confirmed by differential pulse voltammetry. This results support that IrO x nanofibers are good potential sensing materials selectively for AA and/or simultaneously for AA, DA, NADH, UA in complex biological samples.

Original languageEnglish
Pages (from-to)480-488
Number of pages9
JournalSensors and Actuators, B: Chemical
Volume196
DOIs
StatePublished - Jun 2014

Keywords

  • Amperometry
  • Ascorbic acid
  • Electrospinning
  • Iridium oxide
  • Nanofiber
  • Voltammetry

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