Interfacial Electron-Shuttling Processes across KolliphorEL Monolayer Grafted Electrodes

Khadijeh Nekoueian, Christopher E. Hotchen, Mandana Amiri, Mika Sillanpää, Geoffrey W. Nelson, John S. Foord, Philip Holdway, Antoine Buchard, Stephen C. Parker, Frank Marken

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


Covalently grafted KolliphorEL (a poly(ethylene glycol)-based transporter molecule for hydrophobic water-insoluble drugs; MW, ca. 2486; diameter, ca. 3 nm) at the surface of a glassy-carbon electrode strongly affects the rate of electron transfer for aqueous redox systems such as Fe(CN)63-/4-. XPS data confirm monolayer grafting after electrochemical anodization in pure KolliphorEL. On the basis of voltammetry and impedance measurements, the charge transfer process for the Fe(CN)63-/4- probe molecule is completely blocked after KolliphorEL grafting and in the absence of a "guest". However, in the presence of low concentrations of suitable ferrocene derivatives as guests, mediated electron transfer across the monolayer via a shuttle mechanism is observed. The resulting amplification of the ferrocene electroanalytical signal is investigated systematically and compared for five ferrocene derivatives. The low-concentration electron shuttle efficiency decreases in the following sequence: (dimethylaminomethyl)ferrocene > n-butyl ferrocene > ferrocene dimethanol > ferroceneacetonitrile > ferroceneacetic acid.

Original languageEnglish
Pages (from-to)15464-15465
Number of pages2
JournalACS applied materials & interfaces
Issue number28
Publication statusPublished - 22 Jul 2015
Externally publishedYes


  • Cremophor
  • PEGylation
  • amplification
  • sensor
  • tunneling
  • voltammetry

ASJC Scopus subject areas

  • General Materials Science


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