Fabrication of reversible poly(dimethylsiloxane) surfaces via host-guest chemistry and their repeated utilization in cardiac biomarker analysis

Anal Chem. 2011 Dec 15;83(24):9651-9. doi: 10.1021/ac202517x. Epub 2011 Nov 16.

Abstract

On the basis of the host-guest interactions between azobenzenes and cyclodextrins, a new strategy for the preparation of a dually functionalized poly(dimethylsiloxane) (PDMS) surface was investigated using surface-initiated atom-transfer radical polymerization (SI-ATRP) and click chemistry. The PDMS substrates were first oxidized in a H(2)SO(4)/H(2)O(2) solution to transform the surface Si-CH(3) groups into Si-OH groups. Then, the SI-ATRP initiator 3-(2-bromoisobutyramido)propyl(trime-thoxy)silane was grafted onto the substrates through a silanization reaction. Sequentially, the poly(ethylene glycol) (PEG) units were introduced onto the PDMS-Br surfaces via SI-ATRP reaction using oligo(ethylene glycol) methacrylate. Afterward, the bromide groups on the surface were converted to azido groups via nucleophilic substitution reaction with NaN(3). Finally, the azido-grafted PDMS surfaces were subjected to a click reaction with alkynyl and PEG-modified β-cyclodextrins, resulting in the grafting of cyclodextrins onto the PDMS surfaces. The composition and chemical state of the modified surfaces were characterized via X-ray photoelectron spectroscopy, and the stability and dynamic characteristics of the cyclodextrin-modified PDMS substrates were investigated via attenuated total reflection-Fourier transform infrared spectroscopy and temporal contact angle experiments. The surface morphology of the modified PDMS surfaces was characterized through imaging using a multimode atomic force microscope. A protein adsorption assay using Alexa Fluor594-labeled bovine serum albumin, Alexa Fluor594-labeled chicken egg albumin, and FITC-labeled lysozyme shows that the prepared PDMS surfaces possess good protein-repelling properties. On-surface studies on the interactions between azobenzenes and the cyclodextrin-modified surfaces reveal that the reversible binding of azobenzene to the cyclodextrin-modified PDMS surfaces and its subsequent release can be reversibly controlled using UV irradiation. Sandwich fluoroimmunoassay of the cardiac markers myoglobin and fatty acid-binding protein demonstrates that the cyclodextrin-modified PDMS surfaces can be repeatedly utilized in disease biomarker analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azo Compounds / chemistry
  • Biomarkers / analysis*
  • Cardiovascular Diseases / metabolism
  • Cattle
  • Dimethylpolysiloxanes / chemistry*
  • Fatty Acid-Binding Proteins / analysis
  • Fluoroimmunoassay*
  • Humans
  • Muramidase / chemistry
  • Myoglobin / analysis
  • Organic Chemicals / chemistry
  • Photoelectron Spectroscopy
  • Polyethylene Glycols / chemistry
  • Serum Albumin, Bovine / chemistry
  • Surface Properties
  • beta-Cyclodextrins / chemistry

Substances

  • Alexa594
  • Azo Compounds
  • Biomarkers
  • Dimethylpolysiloxanes
  • Fatty Acid-Binding Proteins
  • Myoglobin
  • Organic Chemicals
  • beta-Cyclodextrins
  • Serum Albumin, Bovine
  • Polyethylene Glycols
  • baysilon
  • Muramidase
  • azobenzene