Search results for "Fluorogenic"
showing 10 items of 16 documents
Synthesis of novel organic-based fluorophores – Implementation to the design of fluorogenic enzyme substrates based on the principle of in situ synth…
2020
Detection and fluorescence imaging of biologic systems requires the implementation of efficient, robust and easy-to-use tools. Conventional fluorogenic probes currently used in microbiology lack efficiency since they are based on the single chemical modification of a fluorophore bearing an optically tunable reactive group, which often leads to incomplete fluorescence quenching. The main goal of my Ph.D thesis was to develop novel fluorogenic enzymatic substrates based on the "covalent assembly" principle. This approach also named "in situ synthesis" is based on the use of domino reactions to form a fluorescent moiety starting from a "caged" non-fluorescent molecule. In our case, the bioanal…
Fluorogenic detection of Tetryl and TNT explosives using nanoscopic-capped mesoporous hybrid materials
2013
[EN] A hybrid capped mesoporous material, which was selectively opened in the presence of Tetryl and TNT, has been synthesised and used for the fluorogenic recognition of these nitroaromatic explosives.
Chromogenic and fluorogenic reagents for chemical warfare nerve agents' detection
2008
The ease of production, the extreme toxicity of organophosphorus-containing nerve agents, and their facile use in terrorism attacks underscores the need to develop accurate systems to detect these chemicals. Among different technologies we review here recent advances in the design of chromo-fluorogenic methods for the specific detection of nerve agents. Optical sensing (especially colorimetric detection) requires usually low-cost and widely used instrumentation and offers the possibility of so-called “naked eye detection”. Recent reported examples suggest that the application of chromo-fluorogenic supramolecular concepts for the chromogenic or fluorogenic sensing of nerve agents might be an…
3-Formyl-BODIPY Phenylhydrazone as a Chromo-Fluorogenic Probe for Selective Detection of NO2 (g)
2016
Anew colorimetric and fluorogenic probe,based on a3-formyl boron dipyrromethene (BODIPY)phe-nylhydrazone, for the sensitive and selectivedetectionNO2(g) has been prepared. The probeinsolution experi-ences aremarkablehypsochromic shift of its absorptionand fluorescence emission bands in the presence gaseousNO2(g), leading to limits of detectio noffew ppb. Theprobe also works in the solid phase, adsorbed on filterpaper strips, or chemically immobilized on the surfaceofsilica nanop articles, with limitsofdetection to the nakedeye of about 0.5 ppm.
Addressing subphthalocyanines and subnaphthalocyanines features relevant to fluorescence imaging
2018
International audience; A series of new synthetic subphthalocyanines bear structural features aimed at allowing either fluorescence activation or a bathochromic shift of the absorption band towards the near-infrared window, relevant to optical imaging. X-ray diffraction studies of four subphthalocyanines are reported. Spectrofluorimetric studies on subnaphthalocyanines and activatable subphthalocyanine pro-fluorophores are reported.
Organic-Inorganic Hybrid Mesoporous Materials as Regenerable Sensing Systems for the Recognition of Nitroaromatic Explosives
2013
[EN] Fluorescent organic-inorganic mesoporous hybrid materials have been prepared and characterised, and their behaviour against nitroaromatic explosives have been tested. MCM-41 silica was used as an inorganic scaffold and pyrene (P derivative containing trialkoxysilane moieties), dansyl and fluorescein (D and F derivatives also containing trialkoxysilane groups, respectively) fluorophores have been anchored on hybrid materials by a co-condensation method to obtain a homogenous distribution of dyes into the pores of the support. Six sensing materials have been prepared, of which SP, SD, SF were hydrophilic and SPh, SDh, SFh were hydrophobic. Template-free hydrophilic materials (SP, SD, SF)…
Fluorogenic Sensing of Carcinogenic Bisphenol A using Aptamer-Capped Mesoporous Silica Nanoparticles
2017
[EN] Mesoporous silica nanoparticles loaded with rhodamine B and capped with a bisphenol A aptamer were used for the selective and sensitive detection of this lethal chemical. The pores of the nanoparticles are selectively opened in the presence of bisphenol A (through its selective coordination with the aptamer) with subsequent rhodamine B delivery. With this capped material a limit of detection as low as 3.5 mu m of bisphenol A was measured.
In situ formation of pyronin dyes for fluorescence protease sensing
2017
International audience; We report a reaction-based strategy for the fluorogenic detection of protease activity. Based on the "covalent-assembly" probe design principle recently put forward by the Yang group for detection of Sarin related threats (J. Am. Chem. Soc., 2014, 136, 6594-6597), we have designed two unusual nonfluorescent caged precursors (mixed bis-aryl ethers) which are readily converted into a fluorescent unsymmetrical pyronin dye through a domino cyclisation-aromatisation reaction triggered by penicillin G acylase (PGA) or leucine aminopeptidase (LAP). Fluorescence-based in vitro assays and HPLCfluorescence/- MS analyses support the claimed activation mechanism whose the furthe…
Bacteriochlorin-diketopyrrolopyrrole (DPP) hybrids : New near-infrared fluorophores for biosensing/bioimaging applications
2020
Near-infrared (700-900 nm) absorbing and emitting organic-based fluorophores are valuable tools for bioimaging applications. Indeed, biological component absorption, diffusion and autofluorescence are quite low in this region (known as the first therapeutic window NIR-I), making tissues relatively transparent to these long wavelengths. Bacteriochlorins are porphyrins derivatives in which two double bonds are reduced. These molecules display a strong absorption and emission within NIR-I spectral range. DPPs are structurally simpler fluorophores displaying very interesting properties. They have high fluorescence quantum yields, are highly (photo)chemically and thermally stable. The aim of thi…
Synthèse in situ de fluorophores organiques : formation de liaisons covalentes par déclenchement enzymatique et applications en biodétection
2017
Fluorescence imaging is a growing field of biology over the past decades. Intensive works mainly focused on instrumental developments and chemistry of contrast agents (probes), were already done to improve such bioanalytical technique. The main goal of this Ph. D. thesis was to explore various fluorogenic molecular platforms responsive to various (bio)chemical stimuli and capable of releasing organic fluorophores in the biological medium to analyze. This approach named "in-situsynthesis" is based on domino reactions belonging to the repertoire of "covalent chemistry", triggered by the target (bio)analyte. This kind of process should provide advanced fluorogenic probes with high signal-to-no…