Mechanofluorescent Polymer Brush Surfaces that Spatially Resolve Surface Solvation

Area of Science:

• Surface science
• Polymer chemistry
• Materials science

Background:

• Polymer brushes exhibit stimuli-responsive conformational transitions.
• Transducing these changes into detectable signals is crucial for sensing applications.
• Existing methods lack high-resolution spatial information.

Purpose of the Study:

• To develop polymer brush surfaces with integrated single fluorophores for stimuli detection.
• To enable transduction of polymer conformational changes into measurable fluorescence signals.
• To achieve high-resolution spatial mapping of these transitions.

Main Methods:

• Fabrication of ultrathin (<40 nm) polymer brush surfaces with integrated single fluorophores.
• Utilizing fluorescence lifetime imaging microscopy (FLIM) to monitor conformational changes.
• Correlating changes in fluorophore aggregation and self-quenching with polymer volume transitions.

Main Results:

• Demonstrated that polymer collapse transitions alter fluorophore aggregation and lead to fluorescence self-quenching and reduced lifetimes.
• Successfully mapped polymer brush conformational changes at complex interfaces (air-water-solid, immiscible liquids).
• Identified humidity-controlled polymer brush swelling from vapor phase interactions.

Conclusions:

• Single-fluorophore integrated polymer brushes provide a sensitive platform for surface-based stimuli detection.
• The method offers high-resolution spatial output for understanding polymer phase transitions.
• These surfaces have strong potential for developing novel sensors for various stimuli.