Chain End‐Functionalized Polymer Brushes with Switchable Fluorescence Response

Abstract

Herein is described the switchable fluorescence response of poly(methyl methacrylate) (PMMA) brushes. Chain end fluorescein labeled PMMA brushes are prepared by combining surface‐initiated atom transfer radical polymerization (SI‐ATRP) with a copper‐catalyzed alkyne‐azide cycloaddition (CuAAC) click reaction. Successful attachment of fluorescein is confirmed by measuring fluorescence of the as‐prepared films. Utilizing co‐solvency of PMMA in isopropanol‐water mixtures, responsive behavior of the end‐functionalized brushes is demonstrated by measuring the changes in fluorescence intensity between the swollen and collapsed states.

FRET‐Integrated Polymer Brushes for Spatially Resolved Sensing of Changes in Polymer Conformation

“…Tas et al., reported on polymer brush systems with end‐tethered fluorophores, where the fluorophore exhibited quenching effects which were correlated to the polymer brush height. [19] This has separately been used for microscopically visualizing patterns. [20] These fluorescence‐based approaches offer strong possibilities towards developing more complex polymer brush surfaces that can noninvasively reveal details on polymer conformation, and ultimately sensing of real‐time changes in aqueous solution compositions.…”

Luminescent Surface‐Tethered Polymer Brush Materials

“…The brushes demonstrated solvent‐dependent fluorescence whereby in “good” solvent (IPA/water 80 : 20) green fluorescence is observed, while in “bad” solvent (e. g., pure water or IPA), fluorescence is quenched as a result of aggregation of the fluorophores due to polymer brush collapse. This is in contrast to what is observed for free fluorescein, where in water the fluorescence intensity is increased relative to that of the IPA/water mixture [70] . By functionalizing the chain ends with the fluorescent moiety rather than dispersing it throughout the brush, the authors can limit self‐quenching of the fluorophores when the brushes are in the swollen state.…”

FRET‐Integrated Polymer Brushes for Spatially Resolved Sensing of Changes in Polymer Conformation

“…Tase tal., reported on polymer brush systems with end-tethered fluorophores,where the fluorophore exhibited quenching effects which were correlated to the polymer brush height. [19] This has separately been used for microscopically visualizing patterns. [20] These fluorescence-based approaches offer strong possibilities towards developing more complex polymer brush surfaces that can noninvasively reveal details on polymer conformation, and ultimately sensing of real-time changes in aqueous solution compositions.…”