Electrochemically controlled adsorption of Fc-functionalized polymers on beta-CD-modified self-assembled monolayers

Langmuir. 2010 Sep 7;26(17):13976-86. doi: 10.1021/la102026h.

Abstract

This work presents an in situ study of the adsorption/desorption behavior of ferrocene(Fc)-functionalized linear polymers on a gold surface covered with beta-cyclodextrin(beta-CD)-modified self-assembled monolayers (SAMs). The characterization of binary SAMs obtained with HS-(CH(2))(11)-EG(6)-N(3) and HS-(CH(2))(11)-EG(4)-OH (EG, ethylene glycol) was performed using a quartz crystal microbalance with dissipation monitoring (QCM-D), cyclic voltammetry, and contact angle measurements. The functionalization of SAMs with beta-CD was made via the "click" reaction between the beta-CD monoalkyne derivative and azide groups exhibited by SAMs. The formation of the host-guest complex between SAM-beta-CD and Fc-derivatized polymers (chitosan (CHI) and poly(allylamine hydrochloride) (PAH)) was studied by QCM-D. The viscoelastic model of Voinova was used to fit QCM-D curves recorded during the adsorption and electrochemically controlled desorption of CHI-Fc and PAH-Fc on SAM-beta-CD. Using QCM-D coupled to cyclic voltammetry, we demonstrated that CHI-Fc and PAH-Fc can be successfully deposited on a SAM-beta-CD-coated gold surface forming a stable multivalent inclusion complex between Fc moieties of polymer and beta-CD cavities of SAM. We also showed that all specifically attached polymer chains can be detached from the SAM-beta-CD-coated gold surface by applying an electric field.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Chitosan / chemistry
  • Electrochemistry
  • Ferrous Compounds / chemistry*
  • Gold / chemistry
  • Metallocenes
  • Molecular Structure
  • Polyamines / chemistry*
  • Surface Properties
  • beta-Cyclodextrins / chemistry*

Substances

  • Ferrous Compounds
  • Metallocenes
  • Polyamines
  • beta-Cyclodextrins
  • polyallylamine
  • Gold
  • Chitosan
  • betadex
  • ferrocene