Fast and Spatially Resolved Environmental Probing Using Stimuli-Responsive Polymer Layers and Fluorescent Nanocrystals


  • We thank J. Kerssemakers and J. Helenius for help with the experimental work and J. Feldmann for helpful discussions, as well as K.-J. Eichhorn and R. Schulze for support with the ellipsometry. Andor Technology (Belfast, Northern Ireland) is greatly acknowledged for the generous loan of the high-speed EMCCD camera. The authors are grateful to the DFG (grant SPP 1164) and the BMBF (grant 03N8712) for financial support. S. Sapra is thankful to the Humboldt-Foundation for funding his research stay in Germany.


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Stimuli-responsive polymer brushes with adsorbed fluorescent semiconductor nanocrystals can be used in solvent-sensitive sensors based on the fluorescence-interference contrast (see figure) of semiconductor nanocrystals near a reflecting silicon surface. The reversible, solvent-depending swelling of a thin, surface-anchored film of poly(2-vinyl pyridine) using hydrophobic CdSeS nanocrystals leads to a high temporal and spatial resolution of the fluorescence images.