In situ surface functionalization of plasticized poly(vinyl chloride) membranes by 'click chemistry'

We report here for the first time a universal method to achieve a covalent surface modification of plasticized poly(vinyl chloride) (PVC). A copper(I)-catalyzed azide-alkyne cycloaddition ('click chemistry') is performed on plasticized PVC containing partial azide substitutions. This surface modification is performed under mild conditions after membrane casting and is likely to be generally applicable to electrochemical and optical sensors. The concept is illustrated by attaching fluorescein and sulfonated Nile blue derivatives, as well as tetraethylene glycol to the membrane surface. Characterization by confocal microscopy, ATR-IR, QCM, UV/Vis spectroscopy and pulsed chronopotentiometry supports the surface modification procedure. As an initial example of practical utility, tetraethylene glycol modification is shown to significantly reduce surface adsorption by albumin, as evidenced by QCM and electrochemical experiments.