10 research outputs found

    Ca-NIR: a ratiometric near-infrared calcium probe based on a dihydroxanthene-hemicyanine fluorophore.

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    Fluorescent calcium probes are essential tools for studying the fluctuation of calcium ions in cells. Herein, we developed Ca-NIR, the first ratiometric calcium probe emitting in the near infrared region. This probe arose from the fusion of a BAPTA chelator and a dihydroxanthene-hemicyanine fluorophore. It is efficiently excited with common 630-640 nm lasers and displays two distinct emission bands depending on the calcium concentration (Kd = ∼8 μM). The physicochemical and spectroscopic properties of Ca-NIR allowed for ratiometric imaging of calcium distribution in live cells.journal article2017 Jun 01imported"Supporting information" disponible sur le site de l'éditeu

    PEGylated Red-Emitting Calcium Probe with Improved Sensing Properties for Neuroscience.

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    Monitoring calcium concentration in the cytosol is of main importance as this ion drives many biological cascades within the cell. To this end, molecular calcium probes are widely used. Most of them, especially the red emitting probes, suffer from nonspecific interactions with inner membranes due to the hydrophobic nature of their fluorophore. To circumvent this issue, calcium probes conjugated to dextran can be used to enhance the hydrophilicity and reduce the nonspecific interaction and compartmentalization. However, dextran conjugates also feature important drawbacks including lower affinity, lower dynamic range, and slow diffusion. Herein, we combined the advantage of molecular probes and dextran conjugate without their drawbacks by designing a new red emitting turn-on calcium probe based on PET quenching, Rhod-PEG, in which the rhodamine fluorophore bears four PEG4 units. This modification led to a high affinity calcium probe (Kd = 748 nM) with reduced nonspecific interactions, enhanced photostability, two-photon absorbance, and brightness compared to the commercially available Rhod-2. After spectral characterizations, we showed that Rhod-PEG quickly and efficiently diffused through the dendrites of pyramidal neurons with an enhanced sensitivity (ΔF/F0) at shorter time after patching compared to Rhod-2.journal article2017 Nov 222017 10 24imported"Supporting information" disponible sur le site de l'éditeur à l'adresse suivante : http://pubs.acs.org/doi/suppl/10.1021/acssensors.7b0066

    Hybrides bactériochlorine-dicétopyrrolopyrrole (DPP) : Nouveaux fluorophores proche infrarouge pour des applications en biodétection/bioimagerie

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    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 this thesis is to associate these two fluorophore units in order to yield novel multi-chromophoric molecular architectures that combine their complementary properties. DPP dyes used in the design of the hybrids are highly versatile. They can be used as fluorogenic reporters for the detection of relevant enzymatic activities in the biological media by introducing a specific triggering unit of the targeted analyte and water-solubilizing moieties.Les fluorophores organiques absorbant et émettant dans le proche infrarouge (700-900 nm, première fenêtre thérapeutique NIR-I) sont des outils de choix pour une application en bioimagerie. En effet, l'absorption, la diffusion et l'autofluorescence de constituants du milieu biologiques sont limitées dans cette région spectrale, rendant les tissus relativement transparents à ces longueurs d'onde. Les bactériochlorines sont des dérivés de porphyrines dont deux doubles liaisons sont réduites. Ces molécules présentent une forte absorption et une émission dans le NIR-I. Les DPP sont des fluorophores, structurellement plus simples, aux propriétés très intéressantes. Ils présentent un rendement quantique de fluorescence élevé, un grande photostabilité et sont également très stable chimiquement et thermiquement. L'objectif de cette thèse est d'associer ces deux fluorophores et d'accéder à de nouvelles architectures multi-chromophoriques d'intérêt et combinant leurs propriétés complémentaires. Les DPP utilisés dans la construction de ces structures hybrides, très modulables pourront être adaptés à la détection d'activités enzymatiques d'intérêt en milieu biologique, par introduction d'un motif de reconnaissance spécifique de l'analyte et de groupements hydrosolubilisants

    Hybrides bactériochlorine-dicétopyrrolopyrrole (DPP) : Nouveaux fluorophores proche infrarouge pour des applications en biodétection/bioimagerie

    No full text
    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 this thesis is to associate these two fluorophore units in order to yield novel multi-chromophoric molecular architectures that combine their complementary properties. DPP dyes used in the design of the hybrids are highly versatile. They can be used as fluorogenic reporters for the detection of relevant enzymatic activities in the biological media by introducing a specific triggering unit of the targeted analyte and water-solubilizing moieties.Les fluorophores organiques absorbant et émettant dans le proche infrarouge (700-900 nm, première fenêtre thérapeutique NIR-I) sont des outils de choix pour une application en bioimagerie. En effet, l'absorption, la diffusion et l'autofluorescence de constituants du milieu biologiques sont limitées dans cette région spectrale, rendant les tissus relativement transparents à ces longueurs d'onde. Les bactériochlorines sont des dérivés de porphyrines dont deux doubles liaisons sont réduites. Ces molécules présentent une forte absorption et une émission dans le NIR-I. Les DPP sont des fluorophores, structurellement plus simples, aux propriétés très intéressantes. Ils présentent un rendement quantique de fluorescence élevé, un grande photostabilité et sont également très stable chimiquement et thermiquement. L'objectif de cette thèse est d'associer ces deux fluorophores et d'accéder à de nouvelles architectures multi-chromophoriques d'intérêt et combinant leurs propriétés complémentaires. Les DPP utilisés dans la construction de ces structures hybrides, très modulables pourront être adaptés à la détection d'activités enzymatiques d'intérêt en milieu biologique, par introduction d'un motif de reconnaissance spécifique de l'analyte et de groupements hydrosolubilisants

    Bacteriochlorin-diketopyrrolopyrrole (DPP) hybrids : New near-infrared fluorophores for biosensing/bioimaging applications

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    Les fluorophores organiques absorbant et émettant dans le proche infrarouge (700-900 nm, première fenêtre thérapeutique NIR-I) sont des outils de choix pour une application en bioimagerie. En effet, l'absorption, la diffusion et l'autofluorescence de constituants du milieu biologiques sont limitées dans cette région spectrale, rendant les tissus relativement transparents à ces longueurs d'onde. Les bactériochlorines sont des dérivés de porphyrines dont deux doubles liaisons sont réduites. Ces molécules présentent une forte absorption et une émission dans le NIR-I. Les DPP sont des fluorophores, structurellement plus simples, aux propriétés très intéressantes. Ils présentent un rendement quantique de fluorescence élevé, un grande photostabilité et sont également très stable chimiquement et thermiquement. L'objectif de cette thèse est d'associer ces deux fluorophores et d'accéder à de nouvelles architectures multi-chromophoriques d'intérêt et combinant leurs propriétés complémentaires. Les DPP utilisés dans la construction de ces structures hybrides, très modulables pourront être adaptés à la détection d'activités enzymatiques d'intérêt en milieu biologique, par introduction d'un motif de reconnaissance spécifique de l'analyte et de groupements hydrosolubilisants.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 this thesis is to associate these two fluorophore units in order to yield novel multi-chromophoric molecular architectures that combine their complementary properties. DPP dyes used in the design of the hybrids are highly versatile. They can be used as fluorogenic reporters for the detection of relevant enzymatic activities in the biological media by introducing a specific triggering unit of the targeted analyte and water-solubilizing moieties

    N-Alkylation of 2-Methoxy-10H-Phenothiazine Revisited. A Facile Entry to Diversely N-substituted Phenothiazine-Coumarin Hybrid Dyes

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    N-Alkylation of 2-methoxy-10H-phenothiazine, a valuable building block for the synthesis of bioactive compounds and reaction-based fluorescent probes, has been revisited aimed at introducing a substituent easily convertible into cationic or zwitterionic side chains. We focused our attention on the 3-dimethylaminopropyl group since its derivatization through reactions with various alkyl halides or sultones is a well-established and effective way to enhance polarity of diverse hydrophobic molecular scaffolds. This two-step functionalization approach was applied to the synthesis of novel phenothiazine-coumarin hybrid dyes whose spectral features, especially their NIR-I emission, have been determined in aqueous media with the ultimate goal of identifying novel fluorescent markers for bioanalytical applications, including fluorogenic detection of reactive oxygen species (ROS) through selective S-oxidation reaction of phenothiazine scaffold. </div

    Near-infrared emissive bacteriochlorin-diketopyrrolopyrrole triads: Synthesis and photophysical properties

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    International audienceThe synthesis of unprecedented energy transfer triads containing a near-infrared (NIR) emissive bacteriochlorin subunit and two diketopyrrolopyrrole (DPP) moieties linked to each other via ethynyl or zero-carbon spacers is presented. Their optical and fluorescence properties were determined in CHCl3 and toluene. These photophysical measurements highlight the ability of DPP scaffold to act as an effective energy donor, which once excited in the range 450-550 nm resulting nearly exclusively NIR emission of hydroporphyrin (ETE > 96%). Since DPP dyes are valuable structurally tunable fluorophores that may be used in the construction of high-performance multicomponent photoactive systems, their spectral compatibility with bacteriochlorin chromophore demonstrated through this work, is an important first step toward the rational design of novel and innovative hybrid NIR fluorophores inspired by (bacterio)chlorophylls and suitable for biomedical applications

    Design, Synthesis and Evaluation of Enzyme-Responsive Fluorogenic Probes Based on Pyridine-Flanked Diketopyrrolopyrrole Dyes

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    The ever-growing demand for fluorogenic dyes usable in the rapid construction of analyte-responsive fluorescent probes, has recently contributed to a revival of interest in the chemistry of diketopyrrolopyrrole (DPP) pigments. In this context, we have explored the potential of symmetrical and unsymmetrical DPP derivatives bearing two or one 4-pyridyl substituents acting as optically tunable group(s). The unique fluorogenic behavior of these molecules, closely linked to N-substitution/charge state of their pyridine unit (i.e., neutral pyridine or cationic pyridinium), has been used to design DPP-based fluorescent probes for detection of hypoxia-related redox enzymes and penicillin G acylase (PGA). In this paper, we describe synthesis, spectral characterization and bioanalytical validations of these probes. Dramatic differences in terms of aqueous stability and enzymatic fluorescence activation were observed. This systematic study enables to delineate the scope of application of pyridine-flanked DPP fluorophores in the field of enzyme biosensing

    Design, synthesis and evaluation of enzyme-responsive fluorogenic probes based on pyridine-flanked diketopyrrolopyrrole dyes

    No full text
    International audienceThe ever-growing demand for fluorogenic dyes usable in the rapid construction of analyteresponsive fluorescent probes, has recently contributed to a revival of interest in the chemistry of diketopyrrolopyrrole (DPP) pigments. In this context, we have explored the potential of symmetrical and unsymmetrical DPP derivatives bearing two or one 4-pyridyl substituents acting as optically tunable group(s). The unique fluorogenic behavior of these molecules, closely linked to N-substitution/charge state of their pyridine unit (i.e., neutral pyridine or cationic pyridinium), has been used to design DPP-based fluorescent probes for detection of hypoxia-related redox enzymes and penicillin G acylase (PGA). In this paper, we describe synthesis, spectral characterization and bioanalytical validations of these probes. Dramatic differences in terms of aqueous stability and enzymatic fluorescence activation were observed. This systematic study enables to delineate the scope of application of pyridine-flanked DPP fluorophores in the field of enzyme biosensing
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