Azobenzenes are the most widely studied photoswitches, and have become popular optical probes for biological systems. The cis configuration is normally metastable, meaning trans always thermodynamically favored. unique exception to this rule an azobenzene having a two-carbon bridge between ortho positions, substitutions that lock photoswitch in its configuration. Only thoroughly chemically characterized relatively recently, we describe first applications of locked-azobenzene (or "LAB")...

A coumarin fluorophore and an oxazine photochrome can be integrated within the same molecular skeleton connected covalently to a secondary antibody. Illumination of antibody–dyad conjugate at appropriate activation wavelength opens ring reversibly shifts bathochromically ground-state absorption component. Selective excitation photochemical product then produces significant fluorescence allows detection activated bioconjugates single-molecule level. Such events exploited resolve temporally...

The identification of operating principles to activate fluorescence under the influence external stimulations is essential enable implementation imaging strategies requiring spatiotemporal control emission. In this context, our laboratories designed mechanisms switch with either light or pH based on unique photochemical and photophysical properties photoresponsive halochromic oxazines respectively. These heterocycles can be connected covalently fluorescent chromophores opened impose a...

Seven macromolecular constructs incorporating multiple borondipyrromethene (BODIPY) fluorophores along a common poly(methacrylate) backbone with decyl and oligo(ethylene glycol) side chains were synthesized. The hydrophilic components impose solubility in aqueous environment on the overall assembly. hydrophobic effectively insulate from each other to prevent detrimental interchromophoric interactions preserve their photophysical properties. As result, brightness of these multicomponent...

We designed an autocatalytic photochemical reaction based on the photoinduced cleavage of α-diketone bridge from central phenylene ring a fluorescent anthracene derivative. The product this transformation sensitizes its own formation reactant, under illumination at wavelength capable exciting both species. Specifically, initial and direct excitation reactant generates in ground state. subsequent latter species results transfer energy to another molecule former establish loop. Comparison...

Halochromic coumarin–oxazine prefluorophores and targeting folate ligands can be connected covalently to the side chains of amphiphilic polymers. The resulting macromolecular constructs assemble into nanoparticles in aqueous environments. do not produce any detectable fluorescence at neutral pH, but are converted fluorophores with intense visible emission acidic pH. Protonation opens oxazine heterocycle shift bathochromically coumarin absorption activate a brightness per nanoparticle...

Supramolecular nanocarriers, co-entrapping complementary donors and acceptors in their hydrophobic interior, enable the intracellular generation of singlet oxygen upon NIR excitation.

Fifteen substituted maleimide cycloadducts of anthracene derivatives were synthesized in one or two steps from available precursors yields ranging 32 to 63%. They differ the nature group on nitrogen atom and substituents platform. In all instances, introduction a bridge across positions 9 10 skeleton isolates electronically its peripheral phenylene rings suppresses characteristic fluorescence. The with 4-(dimethylamino)phenyl undergo retro-cycloaddition upon ultraviolet illumination quantum...

A strategy to probe supramolecular nanocarriers and their cargo in the intracellular space was developed on basis of fluorescence measurements energy transfer. It relies covalent attachment an donor, or acceptor, macromolecular backbone amphiphilic polymers noncovalent encapsulation a complementary resulting micelles. In aqueous environments, these macromolecules self-assemble into nanostructured constructs bring chromophores close proximity enable efficient These assemblies travel from...

Key points A new caged nicotinic acetylcholine receptor (nAChR) agonist was developed, ABT594, which is photolysed by one‐ and two‐photon excitation. The compound with a quantum yield of 0.20. One‐photon uncaging ABT594 elicited large currents Ca 2+ transients at the soma dendrites medial habenula (MHb) neurons mouse brain slices. Unexpectedly, also revealed highly ‐permeable nAChRs on axons MHb neurons. Abstract Photochemical release neurotransmitters has been instrumental in study their...

The photoinduced cleavage of oxazine heterocycles, connected to macromolecules spin coated on appropriate substrates, occurs efficiently and irreversibly quench the emission a fluorescent dopant allow imprinting patterns.

Supramolecular nanocarriers transport complementary reactants inside living cells in consecutive internalization steps to allow their reaction exclusively the intracellular space with formation of a fluorescent product.

Ifenprodil is an important negative allosteric modulator of the N-methyl-D-aspartate (NMDA) receptors. We have synthesized caged and photoswitchable derivatives this small molecule drug. Caged ifenprodil was biologically inert before photolysis, UV irradiation efficiently released drug allowing selective inhibition GluN2B-containing NMDA Azobenzene-modified ifenprodil, on other hand, in both its trans cis configurations, although silico modeling predicted form to be able bind receptor. The...

Conjugates of small molecules and antibodies are broadly employed diagnostic therapeutic agents. Appending a molecule to an antibody often significantly impacts the properties resulting conjugate. Here, we detail systematic study investigating effect various functional groups on antibody–fluorophore conjugates. This was done through preparation analysis series masked heptamethine cyanines (CyMasks)-bearing amides with varied groups. These were designed exhibit broad range physical...

Self-assembling nanocarriers of amphiphilic polymers encapsulate hydrophobic fluorophores in their interior and, upon injection <italic>Drosophila melanogaster</italic> embryos, release cargo into the cellular blastoderm.

Fluorescent 3H-indolium cations are valuable components for the realization of activatable fluorophores bioimaging applications. Their relatively poor fluorescent quantum yields in organic solvents, however, appear to be contradiction their good performance analytical methods based on single-molecule detection. The elucidation structural factors governing excitation dynamics these compounds is, therefore, essential rationalize effects and possibly guide future design probes with improved...

Abstract Strategies to regulate the ability of photoactivatable fluorophores absorb activating photons are essential allow their operation under illumination conditions compatible with biological samples. In this context, our laboratories identified a viable synthetic protocol introduce conjugated substituent on photocleavable component BODIPY‐oxazine dyad and enhance its molar absorption coefficient at activation wavelength. This structural transformation translates into four‐fold...

The activation wavelength of a photochromic oxazine can be shifted bathochromically with the introduction methoxy substituent on chromophore responsible for initiating photochemical transformation. This structural modification permits switching under mild illumination conditions, enhances photoisomerization quantum yield and ensures outstanding fatigue resistance. Thus, these results guide design new members this family photoresponsive molecular switches improved photophysical properties.

Abstract The photoinduced decarbonylation of an α‐diketone adduct generates 2,6‐dimethoxyanthracene in the ground state. photochemical product can also absorb incoming photons and transfer its excitation energy to another molecule reactant establish autocatalytic loop. In presence silver nanoparticles, efficiency increases significantly with a concomitant acceleration transformation. principle, this mechanism kinetic amplification be extended any photoactivatable fluorophore, if engineered...

The covalent integration of fluorescent and photoswitchable components within the same molecular skeleton can be exploited to activate fluorescence under optical control. Specifically, a oxazine heterocycle connected either coumarin or borondipyrromethene fluorophore. Illumination resulting dyads at an appropriate activation wavelength opens reversibly cleaves it irreversibly, depending on relative positions its methylene nitro substituents. These photochemical transformations shift...