Surface-Cross-Linked Micelles as Multifunctionalized Organic Nanoparticles for Controlled Release, Light Harvesting, and Catalysis

Abstract

Surfactant micelles are dynamic entities with a rapid exchange of monomers. By “clicking” tripropargylammonium-containing surfactants with diazide cross-linkers, we obtained surface-cross-linked micelles (SCMs) that could be multifunctionalized for different applications. They triggered membrane fusion through tunable electrostatic interactions with lipid bilayers. Antenna chromophores could be installed on them to create artificial light-harvesting complexes with efficient energy migration among tens to hundreds of chromophores. When cleavable cross-linkers were used, the SCMs could break apart in response to redox or pH signals, ejecting entrapped contents quickly as a result of built-in electrostatic stress. They served as caged surfactants whose surface activity was turned on by environmental stimuli. They crossed cell membranes readily. Encapsulated fluorophores showed enhanced photophysical properties including improved quantum yields and greatly expanded Stokes shifts. Catalytic groups could be installed on the surface or in the interior, covalently attached or physically entrapped. As enzyme mimics, the SCMs enabled rational engineering of the microenvironment around the catalysts to afford activity and selectivity not possible with conventional catalysts.

A General Method for Selective Recognition of Monosaccharides and Oligosaccharides in Water

“…As a result, the local concentrations of the reactive groups are exceedingly high on the micelle surface, making the surface cross-linking particularly facile. 44,45 …”

Imprinted micelles for chiral recognition in water: shape, depth, and number of recognition sites

“…Surface-cross-linking of the micelle was achieved using diazide 2 by the Cu(I)-catalyzed click reaction. 38–40 The surface-cross-linked micelle (SCM) had residual alkynyl groups on the surface because the cross-linkable surfactant has three alkynes and the cross-linker two azides—the ratio between the two was 1:1.2 in typical MINP preparation.…”

Selective Recognition of d-Aldohexoses in Water by Boronic Acid-Functionalized, Molecularly Imprinted Cross-Linked Micelles

“…22-24 Template 3 was solubilized in water together with DVB and a photoinitiator (DMPA) by 1 in the very beginning. It was prepared from 4-vinylphenylboroxine and glucose according a literature procedure.…”