Search results for "Fluorophore"
showing 10 items of 71 documents
Derivatization of hydroxyl functional groups for liquid chromatography and capillary electroseparation
2013
The derivatization reactions commonly used to enhance the analytical signal in the HPLC and CE determination of compounds with hydroxyl functional groups are revised. Focus is placed on the determination of compounds having aliphatic alcohols and phenols while lacking other reactive functional groups. The derivatization with acyl chlorides, organic anhydrides, isocyanates and a variety of other approaches, including oxidation of primary and secondary alcohols, sulfonation, esterification with carboxylic acids, and the use of azides, sulfonyl chlorides and other reagents having miscellaneous leaving groups, is covered. Reactions mainly addressed to introduce a chromophore or a fluorophore in…
Hyaluronan-Based Graft Copolymers Bearing Aggregation-Induced Emission Flurogens
2017
In order to develop a technology platform based on two natural compounds from biorenewable resources, a short series of hyaluronan (HA) copolymers grafted with propargylated ferulic acid (HA-FA-Pg) were designed and synthesized to show different grafting degree values and their optical properties were characterized in comparison with reference compounds containing the same ferulate fluorophore. Interestingly, these studies revealed that the ferulate fluorophore was quite sensitive to the restriction of intramolecular motion and its introduction into the rigid HA backbone, as in HA-FA-Pg graft copolymers, led to higher photoluminescence quantum yield values than those obtained with the isola…
Azide and sulfonylazide functionalized fluorophores for the selective and sensitive detection of hydrogen sulfide
2015
[EN] Three fluorescent probes (1–3) for the selective and sensitive detection of hydrogen sulfide have been synthesized and characterized. Probe 1 is a coumarin derivative functionalized with an azide moiety whereas 2 contain the azide reactive group into a naphthalene fluorophore backbone. Probe 3 is composed also by a naphthalene fluorophore but, in this case, functionalized with a sulfonylazide reactive moiety. Probes 1 and 3 are non-fluorescent whereas 2 is weakly emissive in HEPES (10 mM, pH 7.4)–DMSO 99:1 (v/v). The emission behavior of the three probes was tested against selected anions, bio-thiols and oxidant molecules. Of all the chemical species tested, only HS− is able to induce …
Synthesis and Evaluation of Novel Ring‐Strained Noncanonical Amino Acids for Residue‐Specific Bioorthogonal Reactions in Living Cells
2021
Abstract Bioorthogonal reactions are ideally suited to selectively modify proteins in complex environments, even in vivo. Kinetics and product stability of these reactions are crucial parameters to evaluate their usefulness for specific applications. Strain promoted inverse electron demand Diels–Alder cycloadditions (SPIEDAC) between tetrazines and strained alkenes or alkynes are particularly popular, as they allow ultrafast labeling inside cells. In combination with genetic code expansion (GCE)‐a method that allows to incorporate noncanonical amino acids (ncAAs) site‐specifically into proteins in vivo. These reactions enable residue‐specific fluorophore attachment to proteins in living mam…
Gold nanoclusters for ratiometric sensing of pH in extremely acidic media.
2019
AuNCs capped with β-nicotinamide adenine dinucleotide phosphate exhibit an outstanding performance as fluorescent pH sensors; specifically they exhibit a high emission in strongly acidic media and linear dependence on pH in extremely acidic media (0.6–2.7) as well as in the 7.0–9.2 pH range, while they are unresponsive at intermediate pH values. Remarkably, these AuNCs make ratiometric sensing possible in extremely acidic media with a single fluorophore, specifically the nanocluster itself.
Multicomponent polymeric micelles based on polyaspartamide as tunable fluorescent pH-window biosensors
2010
Abstract PHEA-PEG 5000 -C 16 is a polyaspartamide polymer with appended hydrophilic PEG 5000 functions and hydrophobic n-C 16 units forming biocompatible micelles with a CAC as low as 1.8 × 10 −7 M. The protonation and acidity constants of the polymer's amino and carboxylic groups have been determined by potentiometric titrations at five different concentrations higher than CAC, finding concentration-independent values. Viscosity and polarity of the micellar core have been investigated by means of fluorescent probes, finding local values comparable to those of pure toluene and to the core of sodium dodecyl sulphate micelles, independently on the protonation degree of the polymer. The fluor…
A new fluorescent "turn-on" chemodosimeter for the detection of hydrogen sulfide in water and living cells
2013
[EN] A new fluorescent turn-on probe for the selective detection of hydrogen sulfide in water and living cells based on a 8-hydroxyquinoline fluorophore functionalized with a 2,6-dinitrophenyl ether moiety has been developed.
A micellar multitasking device: sensing pH windows and gauging the lipophilicity of drugs with fluorescent signals.
2010
A multitasking fluorescent device can be obtained by forming micelles of Triton X-100, containing a lipophilic macrocyclic Cu(2+) complex and the coordinating fluorophore Coumarin 343 (C343), which features a COOH moiety. At low pH the two micellised components do not interact, and the fluorescence of Courmarin 343 (C343) is intense. At intermediate pH, C343 is deprotonated and coordinates to the Cu(2+) centre in its apical position, with fluorescence quenching. At higher pH the deprotonated C343 is displaced from Cu(2+) by the formation of an OH(-) complex, and the fluorescence is revived. This allows the system to carry out its first task as it behaves as an "on-off-on" fluorescent sensor…
Fluorescent Hg2+ Sensors: Synthesis and Evaluation of a Tren-Based Starburst Molecule Containing Fluorinated 1,2,4-Oxadiazoles.
2010
A new tren-based starburst molecule containing fluorinated 1,2,4-oxadiazoles as fluorophores has been synthesized and its sensing behavior toward several metal cations has been investigated by UV/Vis, fluorescence, 1 H NMR and 19 F NMR spectroscopy. Selective sensing for Hg 2+ ions through a PET-based mechanism was evidenced, suggesting application as fluorescent sensor for Hg 2+ of the off-on type.
A FRET-based probe for fluorescence sensing of sulfide/sulfite analytes, using a novel long-wavelength water-soluble 7-hydroxycoumarin as report…
2015
International audience; A FRET-based fluorescent probe for the detection of sulfide and/or sulfite in aqueous buffer, was constructed by connecting the quencher moiety nitrobenzofurazan (7-nitro-1,2,3-benzoxadiazole, NBD) to a water-soluble 3-(2-benzimidazolyl)-7-hydroxycoumarin carboxylic acid through a piperazine linker. This probe exhibits good selectivity and high sensitivity for sulfite and sulfide over cysteine and other potential analytes. Furthermore, this is one of the few examples of fluorogenic coumarins whose solubility in water is maintained upon its conversion into reaction-based fluorescent probes.