The ability to inhibit an enzyme in a specific tissue with high spatial resolution combined with a readily available antidote should find many biomedical applications. We have accomplished this by taking advantage of the cis-trans photoisomerization of azobenzene molecules. Specifically, we positioned azobenzene moieties within the DNA sequence complementary to a 15-base-long thrombin aptamer a...

Gold nanoparticles (AuNPs) coated with a water-soluble polymer displaying a photoswitchable lower critical solution temperature (LCST) were synthesized, and the photoinduced change in the aggregation state of AuNPs was investigated. The photoactivity of AuNPs was conferred by tethering on the surface a random copolymer of N,N-dimethylacrylamide and N-4-phenylazophenyl acrylamide (P(DMA-co-Azo))...

Two azobenzene α-cyclodextrin based nanovalves are designed, synthesized and assembled on mesoporous silica nanoparticles. Under aqueous conditions, the cyclodextrin cap is tightly bound to the azobenzene moiety and capable of holding back loaded cargo molecules. Upon irradiation with a near-UV light laser, trans to cis-photoisomerization of azobenzene initiates a dethreading process, which cau...

Some organic molecules can be isomerized upon photoirradiation and when accompanied by a change in the visible absorption spectrum, it is called photochromism. Azobenzenes are important part of molecular machines and nanotechnology, Which are This phenomenon is called photoisomerization Azobenzene (azo) chromophores , and have been incorporated into a wide variety of materials and molecular arc...

Azobenzene photoresponsive elements can be installed on sulfonylureas, yielding optical control over pancreatic beta cell function and insulin release. An obstacle to such photopharmacological approaches remains the use of ultraviolet-blue illumination. Herein, we synthesize and test a novel yellow light-activated sulfonylurea based on a heterocyclic azobenzene bearing a push-pull system.

A diamide armed with a photochromic azobenzene unit and a nucleophilic pyridyl group varied its aggregation/dissociation state depending on the trans/cis geometry of the azobenzene. The catalytic activity of the pyridyl group was closely linked to the aggregation/dissociation state and hence photoirradiation could manipulate the catalytic performance.

New polyanionic and polyzwitterionic azobenzene ionic liquid-functionalized silica materials were designed based on the preparation of a new polymerizable azobenzene anionic monomer and either its cation-exchange with alkylimidazolium after grafting or the formation of an ionic liquid monomer pair before grafting onto silica.

Highly ordered lamellar polydiacetylene nanocomposites are synthesized by assembling polydiacetylene and azobenzene through a ready solution process. The trans-to-cis transition of azobenzene under UV light induces a conformational change of polydiacetylene with a color change from blue to red.

We demonstrate a new type of anisotropy in thin films of amorphous azobenzene polymers induced between 570 and 633 nm, where the absorbance in the film is on the order of 0.05. The anisotropy has a pronounced radial contribution. This observation points to an additional mechanism for the alignment of azobenzene molecules.

An azobenzene-containing heteropolymer gel in an ionic liquid exhibits thermally reversible volume phase transition when the azobenzene moiety mainly exists in the cis-state, whereas the transition becomes irreversible when it is in the trans-state and an interlocked collapsed state is stabilized; however, the unlocking of the metastable state occurs by UV light irradiation.