Photochemical Disruption of Polyelectrolyte Multilayers

Abstract

Photoreactive polyelectrolyte multilayers (PEMs) that dissolve upon UV irradiation are described. Light-induced switching of the formal charge of a photoreactive polycation resulted in repulsive interlayer electrostatic forces, and caused the dissolution of PEM films. Combining both photoreactive and inert polycations in the same film yielded additional control over the light-induced change in film thickness.

Nanoplasmonic smooth silica versus porous calcium carbonate bead biosensors for detection of biomarkers

“…and films [63][64][65][66][67] wherein detection of molecules can take place at the surface of the polyelectrolyte shell by means of incorporated nanoparticles [68] and nanostructures [69]. Its detection capabilities together with release [70][71][72][73][74][75][76][77][78] and intracellular release [79][80][81] offer extensive opportunities for cell biology and bio-sensing. Figure 8 (online color at: www.ann-phys.org) SERS spectra of BSA molecules (water solution with concentration 1 mg/mL) were acquired from Raman signals were acquired both from surface of the CaCO 3 microparticles filled with gold nanoparticles and SiO 2 terminated gold nanoparticles respectively.…”

Stimuli‐Responsive Free‐Standing Layer‐By‐Layer Films

“…LbL films have been designed to respond to a number of stimuli, including pH, temperature, electrochemical potential, protein–ligand interactions, enzymatic catalysis, and mechanical force . In addition to the work of other groups, our group has been interested in light‐responsive LbL films . Examples we have reported comprise polycations with photocleavable benzylic esters that yield carboxylic acid groups as polymer side chains upon irradiation with light.…”

Dye-functionalized polymers via ring opening metathesis polymerization: principal routes and applications

“…Hydrogels cross-linked with o-nitrobenzylester units can be de-crosslinked upon irradiation [103]. This was also used for dissolving thin films prepared by layer-by-layer adsorption technique by disturbing the electrostatic balance within these films [104]. The change in surface polarity due to the formation of the carboxylic acid can also be used to influence electrical characteristics of organic thin film transistors based on pentacene, either via influencing the growth of pentacene from the vapor phase [105] or influencing the charge concentration in the conductive channel [106].…”