Ultrathin polytyramine films by electropolymerisation on highly doped p-type silicon electrodes

Dusan Losic, Martin Cole, Helmut Thissen, Nicolas H. Voelcker

Research output: Contribution to journalArticleResearchpeer-review

20 Citations (Scopus)

Abstract

In recent years, silicon-based materials have been used extensively in device fabrication for sensors, microfluidic and biomaterial applications. In order to enhance the performance of the material, a number of surface functionalisations are employed. However, until now, silicon has not been used as an electrode material for electrodeposition of functional polymers. Here, highly doped p-type silicon was used as an electrode facilitating the electropolymerisation of ultrathin polytyramine (PT) films by cyclic voltammetry. The influence of resistivity, pre-treatment of the silicon surface and electrochemical conditions on the electropolymerisation process was studied. The results show that ultrathin PT films with a controlled thickness from 2 to 15 nm exhibit good electrochemical stability in buffer solution (pH 6.8) over a large potential window (-1.5 V to 1.5 V) and passivating properties towards a redox probe. In terms of the film morphology, a pinhole-free smooth surface with a roughness below 0.5 nm and with dominantly globular features of 40-60 nm diameter was observed by AFM. XPS characterisation showed that PT films display amine functional groups at the coating surface. UV induced silicon oxidation was used to prepare patterned PT films.

Original languageEnglish
Pages (from-to)245-257
Number of pages13
JournalSurface Science
Volume584
Issue number2-3
DOIs
Publication statusPublished - 20 Jun 2005
Externally publishedYes

Keywords

  • Atomic force microscopy
  • Cyclic voltammetry
  • Electrochemical methods
  • Electropolymerisation
  • Growth
  • Insulating films
  • Polytyramine
  • Silicon
  • Surface chemical reaction
  • Surface structure
  • X-ray photoelectron spectroscopy

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