2021
|
Electrochemical Fluorescence Switch of Organic Fluorescent or Fluorogenic Molecules Article de journal M Guille-Collignon; J M Delacotte; F Lemaitre; E Labbe; O Buriez Chemical Record, 21 (9), p. 2193-2202, 2021. @article{,
title = {Electrochemical Fluorescence Switch of Organic Fluorescent or Fluorogenic Molecules},
author = {M Guille-Collignon and J M Delacotte and F Lemaitre and E Labbe and O Buriez},
url = {https://doi.org/10.1002/tcr.202100022},
doi = {10.1002/tcr.202100022},
year = {2021},
date = {2021-09-01},
journal = {Chemical Record},
volume = {21},
number = {9},
pages = {2193-2202},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
Finding Adapted Quinones for Harvesting Electrons from Photosynthetic Algae Suspensions Article de journal A Sayegh; L A Perego; M A Romero; L Escudero; J Delacotte; M Guille-Collignon; L Grimaud; B Bailleul; F Lemaitre Chemelectrochem, 8 (15), p. 2968-2978, 2021. @article{,
title = {Finding Adapted Quinones for Harvesting Electrons from Photosynthetic Algae Suspensions},
author = {A Sayegh and L A Perego and M A Romero and L Escudero and J Delacotte and M Guille-Collignon and L Grimaud and B Bailleul and F Lemaitre},
url = {https://doi.org/10.1002/celc.202100757},
doi = {10.1002/celc.202100757},
year = {2021},
date = {2021-08-01},
journal = {Chemelectrochem},
volume = {8},
number = {15},
pages = {2968-2978},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
Finding Adapted Quinones for Harvesting Electrons from Photosynthetic Algae Suspensions Article de journal A Sayegh; L A Perego; M A Romero; L Escudero; J Delacotte; M Guille-Collignon; L Grimaud; B Bailleul; F Lemaitre Chemelectrochem, 8 (15), p. 2968-2978, 2021. @article{,
title = {Finding Adapted Quinones for Harvesting Electrons from Photosynthetic Algae Suspensions},
author = {A Sayegh and L A Perego and M A Romero and L Escudero and J Delacotte and M Guille-Collignon and L Grimaud and B Bailleul and F Lemaitre},
url = {https://doi.org/10.1002/celc.202100757},
doi = {10.1002/celc.202100757},
year = {2021},
date = {2021-08-01},
journal = {Chemelectrochem},
volume = {8},
number = {15},
pages = {2968-2978},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
Recent Developments Concerning the Investigation of Exocytosis with Amperometry Article de journal M Guille-Collignon; F Lemaitre Current Opinion in Electrochemistry, 29 , p. 100751, 2021. @article{,
title = {Recent Developments Concerning the Investigation of Exocytosis with Amperometry},
author = {M Guille-Collignon and F Lemaitre},
url = {https://doi.org/10.1016/j.coelec.2021.100751},
doi = {10.1016/j.coelec.2021.100751},
year = {2021},
date = {2021-01-01},
journal = {Current Opinion in Electrochemistry},
volume = {29},
pages = {100751},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
Simulations of amperometric monitoring of exocytosis: moderate pH variations within the cell-electrode cleft with the buffer diffusion Article de journal Y Bouret; M Guille-Collignon; F Lemaitre Analytical and Bioanalytical Chemistry, 2021. @article{,
title = {Simulations of amperometric monitoring of exocytosis: moderate pH variations within the cell-electrode cleft with the buffer diffusion},
author = {Y Bouret and M Guille-Collignon and F Lemaitre},
url = {https://doi.org/10.1007/s00216-021-03443-z},
doi = {10.1007/s00216-021-03443-z},
year = {2021},
date = {2021-01-01},
journal = {Analytical and Bioanalytical Chemistry},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2020
|
Overview and outlook of the strategies devoted to electrofluorescence surveys: Application to single cell secretion analysis Article de journal M Guille-Collignon; F Lemaitre Trac-Trends in Analytical Chemistry, 132 , p. 116055, 2020. @article{,
title = {Overview and outlook of the strategies devoted to electrofluorescence surveys: Application to single cell secretion analysis},
author = {M Guille-Collignon and F Lemaitre},
url = {https://doi.org/10.1016/j.trac.2020.116055},
doi = {10.1016/j.trac.2020.116055},
year = {2020},
date = {2020-11-01},
journal = {Trac-Trends in Analytical Chemistry},
volume = {132},
pages = {116055},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
2019
|
A Fluorescent False Neurotransmitter as a Dual Electrofluorescent Probe for Secretory Cell Models Article de journal J Pandard; N Pan; D H Ebene; T Le Saux; E Ait-Yahiatène; X Liu; L Grimaud; O Buriez; E Labbé; F Lemaître; M Guille-Collignon ChemPlusChem, 84 (10), p. 1578-1586, 2019, (cited By 0). @article{Pandard20191578,
title = {A Fluorescent False Neurotransmitter as a Dual Electrofluorescent Probe for Secretory Cell Models},
author = {J Pandard and N Pan and D H Ebene and T Le Saux and E Ait-Yahiat\`{e}ne and X Liu and L Grimaud and O Buriez and E Labb\'{e} and F Lema\^{i}tre and M Guille-Collignon},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85073931778&doi=10.1002%2fcplu.201900385&partnerID=40&md5=a526291d966e7dc926b44e97c73794b3},
doi = {10.1002/cplu.201900385},
year = {2019},
date = {2019-01-01},
journal = {ChemPlusChem},
volume = {84},
number = {10},
pages = {1578-1586},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
|
Diverting photosynthetic electrons from suspensions of Chlamydomonas reinhardtii algae - New insights using an electrochemical well device Article de journal A Sayegh; G Longatte; O Buriez; F -A Wollman; M Guille-Collignon; E Labbé; J Delacotte; F Lemaître Electrochimica Acta, 304 , p. 465 - 473, 2019, ISSN: 0013-4686. @article{SAYEGH2019465,
title = {Diverting photosynthetic electrons from suspensions of Chlamydomonas reinhardtii algae - New insights using an electrochemical well device},
author = {A Sayegh and G Longatte and O Buriez and F -A Wollman and M Guille-Collignon and E Labb\'{e} and J Delacotte and F Lema\^{i}tre},
url = {http://www.sciencedirect.com/science/article/pii/S0013468619303718},
doi = {https://doi.org/10.1016/j.electacta.2019.02.105},
issn = {0013-4686},
year = {2019},
date = {2019-01-01},
journal = {Electrochimica Acta},
volume = {304},
pages = {465 - 473},
abstract = {In the last years, many strategies have been developed to benefit from oxygenic photosynthesis in the present context of renewable energies. To achieve this, bioelectricity may be produced by using photosynthetic components involved in anodic or cathodic compartments. In this respect, harvesting photosynthetic electrons from living biological systems appears to be an encouraging approach. However it raises the question of the most suitable electrochemical device. In this work, we describe and analyze the performances of an electrochemical device based on a millimeter sized well involving a gold surface as a working electrode. Photocurrents were generated by suspensions of Chlamydomonas reinhardtii algae using quinones as mediators under different experimental conditions. Chronoamperometry and cyclic voltammetry measurements gave insight into the use of this device to investigate important issues (harvesting and poisoning by quinones, photoinactivation…). Furthermore, by introducing a kinetic model originally developed for homogeneous catalytic systems, the kinetics of the electron diverting from this system (Chlamydomonas reinhardtii algae + 2,6-DCBQ + miniaturized setup) can be estimated. All these results demonstrate that this experimental configuration is suitable for future works devoted to the choice of the best parameters in terms of long lasting performances.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the last years, many strategies have been developed to benefit from oxygenic photosynthesis in the present context of renewable energies. To achieve this, bioelectricity may be produced by using photosynthetic components involved in anodic or cathodic compartments. In this respect, harvesting photosynthetic electrons from living biological systems appears to be an encouraging approach. However it raises the question of the most suitable electrochemical device. In this work, we describe and analyze the performances of an electrochemical device based on a millimeter sized well involving a gold surface as a working electrode. Photocurrents were generated by suspensions of Chlamydomonas reinhardtii algae using quinones as mediators under different experimental conditions. Chronoamperometry and cyclic voltammetry measurements gave insight into the use of this device to investigate important issues (harvesting and poisoning by quinones, photoinactivation…). Furthermore, by introducing a kinetic model originally developed for homogeneous catalytic systems, the kinetics of the electron diverting from this system (Chlamydomonas reinhardtii algae + 2,6-DCBQ + miniaturized setup) can be estimated. All these results demonstrate that this experimental configuration is suitable for future works devoted to the choice of the best parameters in terms of long lasting performances. |
Electroactive fluorescent false neurotransmitter FFN102 partially replaces dopamine in PC12 cell vesicles Article de journal L Hu; A Savy; L Grimaud; M Guille-Collignon; F Lemaître; C Amatore; J Delacotte Biophysical Chemistry, 245 , p. 1–5, 2019. @article{Hu:2019,
title = {Electroactive fluorescent false neurotransmitter FFN102 partially replaces dopamine in PC12 cell vesicles},
author = {L Hu and A Savy and L Grimaud and M Guille-Collignon and F Lema\^{i}tre and C Amatore and J Delacotte},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85057201704&doi=10.1016%2fj.bpc.2018.11.001&partnerID=40&md5=28655b4c152ce0fc51fc037feefcff97},
doi = {10.1016/j.bpc.2018.11.001},
year = {2019},
date = {2019-01-01},
journal = {Biophysical Chemistry},
volume = {245},
pages = {1--5},
abstract = {In the last decade, following fluorescent dyes and protein tags, pH sensitive false fluorescent neurotransmitters (FFN) were introduced and were valuable for labeling secretory vesicles and monitoring exocytosis at living cells. In particular, the synthetic analog of neurotransmitters FFN102 was shown to be an electroactive probe. Here, we show that FFN102 is suitable to be used as a bioanalytic probe at the widely used PC12 cell model. FFN102 was uptaken in the secretory vesicles of PC12 cells, partially replacing the endogenous dopamine stored in these vesicles. The different oxidation potentials of dopamine and FFN102 allowed to determine that ca. 12% of dopamine was replaced by FFN102. Moreover, the FFN102 was found to be over released through the initial fusion pore suggesting that it was mostly uptaken in fast diffusion compartment of the vesicles. © 2018 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the last decade, following fluorescent dyes and protein tags, pH sensitive false fluorescent neurotransmitters (FFN) were introduced and were valuable for labeling secretory vesicles and monitoring exocytosis at living cells. In particular, the synthetic analog of neurotransmitters FFN102 was shown to be an electroactive probe. Here, we show that FFN102 is suitable to be used as a bioanalytic probe at the widely used PC12 cell model. FFN102 was uptaken in the secretory vesicles of PC12 cells, partially replacing the endogenous dopamine stored in these vesicles. The different oxidation potentials of dopamine and FFN102 allowed to determine that ca. 12% of dopamine was replaced by FFN102. Moreover, the FFN102 was found to be over released through the initial fusion pore suggesting that it was mostly uptaken in fast diffusion compartment of the vesicles. © 2018 Elsevier B.V. |
2018
|
Coupling electrochemistry and TIRF-microscopy with the fluorescent false neurotransmitter FFN102 supports the fluorescence signals during single vesicle exocytosis detection Article de journal X Liu; L Hu; N Pan; L Grimaud; E Labbé; O Buriez; J Delacotte; F Lemaître; M Guille-Collignon Biophysical Chemistry, 235 , p. 48–55, 2018. @article{Liu:2018,
title = {Coupling electrochemistry and TIRF-microscopy with the fluorescent false neurotransmitter FFN102 supports the fluorescence signals during single vesicle exocytosis detection},
author = {X Liu and L Hu and N Pan and L Grimaud and E Labb\'{e} and O Buriez and J Delacotte and F Lema\^{i}tre and M Guille-Collignon},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042352158&doi=10.1016%2fj.bpc.2018.02.004&partnerID=40&md5=365430d79a0d526895e755729264d88f},
doi = {10.1016/j.bpc.2018.02.004},
year = {2018},
date = {2018-01-01},
journal = {Biophysical Chemistry},
volume = {235},
pages = {48--55},
abstract = {Applications of the Fluorescent False Neurotransmitter FFN102, an analog of biogenic neurotransmitters and a suitable probe for coupled amperometry and TIRFM (total internal reflexion fluorescence microscopy) investigations of exocytotic secretion, were considered here. The electroactivity of FFN102 was shown to very likely arise from the oxidation of its phenolic group through a CE (Chemical-Electrochemical) mechanism. Evidences that the aminoethyl group of FFN102 is the key recognition element by BON N13 cells were also provided. Amperometric measurements were then performed at the single cell level with carbon fiber electrode (CFE) or Indium Tin Oxide (ITO) surfaces. It proved the disparity of kinetic and quantitative parameters of FFN102-stained cells acquired either at cell top and bottom. Moreover, coupled analyses of FFN102 loaded vesicles allowed us to classify three types of optical signals that probably arise from secretion releases thanks to their concomitant detection with an electrochemical spike. Finally, preliminary benefits from the coupling involving FFN102 were reported in terms of origins of overlapped amperometric spikes or assignment of fluorescence extinctions to real exocytotic events. © 2018 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Applications of the Fluorescent False Neurotransmitter FFN102, an analog of biogenic neurotransmitters and a suitable probe for coupled amperometry and TIRFM (total internal reflexion fluorescence microscopy) investigations of exocytotic secretion, were considered here. The electroactivity of FFN102 was shown to very likely arise from the oxidation of its phenolic group through a CE (Chemical-Electrochemical) mechanism. Evidences that the aminoethyl group of FFN102 is the key recognition element by BON N13 cells were also provided. Amperometric measurements were then performed at the single cell level with carbon fiber electrode (CFE) or Indium Tin Oxide (ITO) surfaces. It proved the disparity of kinetic and quantitative parameters of FFN102-stained cells acquired either at cell top and bottom. Moreover, coupled analyses of FFN102 loaded vesicles allowed us to classify three types of optical signals that probably arise from secretion releases thanks to their concomitant detection with an electrochemical spike. Finally, preliminary benefits from the coupling involving FFN102 were reported in terms of origins of overlapped amperometric spikes or assignment of fluorescence extinctions to real exocytotic events. © 2018 Elsevier B.V. |
Downstream Simultaneous Electrochemical Detection of Primary Reactive Oxygen and Nitrogen Species Released by Cell Populations in an Integrated Microfluidic Device Article de journal Y Li; C Sella; F Lemaître; M Guille-Collignon; C Amatore; L Thouin Analytical Chemistry, 90 (15), p. 9386–9394, 2018. @article{Li:2018,
title = {Downstream Simultaneous Electrochemical Detection of Primary Reactive Oxygen and Nitrogen Species Released by Cell Populations in an Integrated Microfluidic Device},
author = {Y Li and C Sella and F Lema\^{i}tre and M Guille-Collignon and C Amatore and L Thouin},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049664645&doi=10.1021%2facs.analchem.8b02039&partnerID=40&md5=8f713011165b3b5e06d267ffccea9277},
doi = {10.1021/acs.analchem.8b02039},
year = {2018},
date = {2018-01-01},
journal = {Analytical Chemistry},
volume = {90},
number = {15},
pages = {9386--9394},
abstract = {An innovative microfluidic platform was designed to monitor electrochemically four primary reactive oxygen (ROS) and reactive nitrogen species (RNS) released by aerobic cells. Taking advantage of the space confinement and electrode performances under flow conditions, only a few experiments were sufficient to directly provide significant statistical data relative to the average behavior of cells during oxidative-stress bursts. The microfluidic platform comprised an upstream microchamber for cell culture and four parallel microchannels located downstream for separately detecting H2O2, ONOO-, NO·, and NO2 -. Amperometric measurements were performed at highly sensitive Pt-black electrodes implemented in the microchannels. RAW 264.7 macrophage secretions triggered by a calcium ionophore were used as a way to assess the performance, sensitivity, and specificity of the integrated microfluidic device. In comparison with some previous evaluations achieved from single-cell measurements, reproducible and relevant determinations validated the proof of concept of this microfluidic platform for analyzing statistically significant oxidative-stress responses of various cell types. Copyright © 2018 American Chemical Society.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An innovative microfluidic platform was designed to monitor electrochemically four primary reactive oxygen (ROS) and reactive nitrogen species (RNS) released by aerobic cells. Taking advantage of the space confinement and electrode performances under flow conditions, only a few experiments were sufficient to directly provide significant statistical data relative to the average behavior of cells during oxidative-stress bursts. The microfluidic platform comprised an upstream microchamber for cell culture and four parallel microchannels located downstream for separately detecting H2O2, ONOO-, NO·, and NO2 -. Amperometric measurements were performed at highly sensitive Pt-black electrodes implemented in the microchannels. RAW 264.7 macrophage secretions triggered by a calcium ionophore were used as a way to assess the performance, sensitivity, and specificity of the integrated microfluidic device. In comparison with some previous evaluations achieved from single-cell measurements, reproducible and relevant determinations validated the proof of concept of this microfluidic platform for analyzing statistically significant oxidative-stress responses of various cell types. Copyright © 2018 American Chemical Society. |
Investigation of photocurrents resulting from a living unicellular algae suspension with quinones over time Article de journal G Longatte; A Sayegh; J Delacotte; F Rappaport; F -A Wollman; M Guille-Collignon; F Lemaître Chemical Science, 9 (43), p. 8271–8281, 2018. @article{Longatte:2018,
title = {Investigation of photocurrents resulting from a living unicellular algae suspension with quinones over time},
author = {G Longatte and A Sayegh and J Delacotte and F Rappaport and F -A Wollman and M Guille-Collignon and F Lema\^{i}tre},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056308267&doi=10.1039%2fc8sc03058h&partnerID=40&md5=73d658b7ab313cc1a772ca28dc56aa2d},
doi = {10.1039/c8sc03058h},
year = {2018},
date = {2018-01-01},
journal = {Chemical Science},
volume = {9},
number = {43},
pages = {8271--8281},
abstract = {Plants, algae, and some bacteria convert solar energy into chemical energy by using photosynthesis. In light of the current energy environment, many research strategies try to benefit from photosynthesis in order to generate usable photobioelectricity. Among all the strategies developed for transferring electrons from the photosynthetic chain to an outer collecting electrode, we recently implemented a method on a preparative scale (high surface electrode) based on a Chlamydomonas reinhardtii green algae suspension in the presence of exogenous quinones as redox mediators. While giving rise to an interesting performance (10-60 μA cm-2) in the course of one hour, this device appears to cause a slow decrease of the recorded photocurrent. In this paper, we wish to analyze and understand this gradual fall in performance in order to limit this issue in future applications. We thus first show that this kind of degradation could be related to over-irradiation conditions or side-effects of quinones depending on experimental conditions. We therefore built an empirical model involving a kinetic quenching induced by incubation with quinones, which is globally consistent with the experimental data provided by fluorescence measurements achieved after dark incubation of algae in the presence of quinones. © 2018 The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Plants, algae, and some bacteria convert solar energy into chemical energy by using photosynthesis. In light of the current energy environment, many research strategies try to benefit from photosynthesis in order to generate usable photobioelectricity. Among all the strategies developed for transferring electrons from the photosynthetic chain to an outer collecting electrode, we recently implemented a method on a preparative scale (high surface electrode) based on a Chlamydomonas reinhardtii green algae suspension in the presence of exogenous quinones as redox mediators. While giving rise to an interesting performance (10-60 μA cm-2) in the course of one hour, this device appears to cause a slow decrease of the recorded photocurrent. In this paper, we wish to analyze and understand this gradual fall in performance in order to limit this issue in future applications. We thus first show that this kind of degradation could be related to over-irradiation conditions or side-effects of quinones depending on experimental conditions. We therefore built an empirical model involving a kinetic quenching induced by incubation with quinones, which is globally consistent with the experimental data provided by fluorescence measurements achieved after dark incubation of algae in the presence of quinones. © 2018 The Royal Society of Chemistry. |
Redox switchable rhodamine-ferrocene dyad: Exploring imaging possibilities in cells Article de journal M Čížková; L Cattiaux; J Pandard; M Guille-Collignon; F Lemaître; J Delacotte; J -M Mallet; E Labbé; O Buriez Electrochemistry Communications, 97 , p. 46–50, 2018. @article{Cizkova:2018,
title = {Redox switchable rhodamine-ferrocene dyad: Exploring imaging possibilities in cells},
author = {M \v{C}\'{i}\v{z}kov\'{a} and L Cattiaux and J Pandard and M Guille-Collignon and F Lema\^{i}tre and J Delacotte and J -M Mallet and E Labb\'{e} and O Buriez},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054592456&doi=10.1016%2fj.elecom.2018.10.009&partnerID=40&md5=10a4aed1c89bb6a788a2a260bbd0a818},
doi = {10.1016/j.elecom.2018.10.009},
year = {2018},
date = {2018-01-01},
journal = {Electrochemistry Communications},
volume = {97},
pages = {46--50},
abstract = {An original redox-responsive fluorescent probe combining a rhodamine derivative and a ferrocenyl moiety used as the fluorescence modulator was designed, synthesized and characterized. The fluorescence of this new dyad could be tuned from the redox state of ferrocene, a feature observed both electrochemically and on cancer cells incubated with this probe. © 2018 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
An original redox-responsive fluorescent probe combining a rhodamine derivative and a ferrocenyl moiety used as the fluorescence modulator was designed, synthesized and characterized. The fluorescence of this new dyad could be tuned from the redox state of ferrocene, a feature observed both electrochemically and on cancer cells incubated with this probe. © 2018 Elsevier B.V. |
2017
|
A Dual Functional Electroactive and Fluorescent Probe for Coupled Measurements of Vesicular Exocytosis with High Spatial and Temporal Resolution Article de journal X Liu; A Savy; S Maurin; L Grimaud; F Darchen; D Quinton; E Labbé; O Buriez; J Delacotte; F Lemaître; M Guille-Collignon Angewandte Chemie - International Edition, 56 (9), p. 2366–2370, 2017. @article{Liu:2017a,
title = {A Dual Functional Electroactive and Fluorescent Probe for Coupled Measurements of Vesicular Exocytosis with High Spatial and Temporal Resolution},
author = {X Liu and A Savy and S Maurin and L Grimaud and F Darchen and D Quinton and E Labb\'{e} and O Buriez and J Delacotte and F Lema\^{i}tre and M Guille-Collignon},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010696856&doi=10.1002%2fanie.201611145&partnerID=40&md5=a51767157166d7f185f0195a28b347b8},
doi = {10.1002/anie.201611145},
year = {2017},
date = {2017-01-01},
journal = {Angewandte Chemie - International Edition},
volume = {56},
number = {9},
pages = {2366--2370},
abstract = {In this work, Fluorescent False Neurotransmitter 102 (FFN102), a synthesized analogue of biogenic neurotransmitters, was demonstrated to show both pH-dependent fluorescence and electroactivity. To study secretory behaviors at the single-vesicle level, FFN102 was employed as a new fluorescent/electroactive dual probe in a coupled technique (amperometry and total internal reflection fluorescence microscopy (TIRFM)). We used N13 cells, a stable clone of BON cells, to specifically accumulate FFN102 into their secretory vesicles, and then optical and electrochemical measurements of vesicular exocytosis were experimentally achieved by using indium tin oxide (ITO) transparent electrodes. Upon stimulation, FFN102 started to diffuse out from the acidic intravesicular microenvironment to the neutral extracellular space, leading to fluorescent emissions and to the electrochemical oxidation signals that were simultaneously collected from the ITO electrode surface. The correlation of fluorescence and amperometric signals resulting from the FFN102 probe allows real-time monitoring of single exocytotic events with both high spatial and temporal resolution. This work opens new possibilities in the investigation of exocytotic mechanisms. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, Fluorescent False Neurotransmitter 102 (FFN102), a synthesized analogue of biogenic neurotransmitters, was demonstrated to show both pH-dependent fluorescence and electroactivity. To study secretory behaviors at the single-vesicle level, FFN102 was employed as a new fluorescent/electroactive dual probe in a coupled technique (amperometry and total internal reflection fluorescence microscopy (TIRFM)). We used N13 cells, a stable clone of BON cells, to specifically accumulate FFN102 into their secretory vesicles, and then optical and electrochemical measurements of vesicular exocytosis were experimentally achieved by using indium tin oxide (ITO) transparent electrodes. Upon stimulation, FFN102 started to diffuse out from the acidic intravesicular microenvironment to the neutral extracellular space, leading to fluorescent emissions and to the electrochemical oxidation signals that were simultaneously collected from the ITO electrode surface. The correlation of fluorescence and amperometric signals resulting from the FFN102 probe allows real-time monitoring of single exocytotic events with both high spatial and temporal resolution. This work opens new possibilities in the investigation of exocytotic mechanisms. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim |
Electrocatalytic Mechanism Involving Michaelis–Menten Kinetics at the Preparative Scale: Theory and Applicability to Photocurrents from a Photosynthetic Algae Suspension With Quinones Article de journal G Longatte; M Guille-Collignon; F Lemaître ChemPhysChem, 18 (19), p. 2643–2650, 2017. @article{Longatte:2017a,
title = {Electrocatalytic Mechanism Involving Michaelis\textendashMenten Kinetics at the Preparative Scale: Theory and Applicability to Photocurrents from a Photosynthetic Algae Suspension With Quinones},
author = {G Longatte and M Guille-Collignon and F Lema\^{i}tre},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85028605961&doi=10.1002%2fcphc.201700351&partnerID=40&md5=0500ecaa88d980132140883a725bedfb},
doi = {10.1002/cphc.201700351},
year = {2017},
date = {2017-01-01},
journal = {ChemPhysChem},
volume = {18},
number = {19},
pages = {2643--2650},
abstract = {In the past years, many strategies have been implemented to benefit from oxygenic photosynthesis to harvest photosynthetic electrons and produce a significant photocurrent. Therefore, electrochemical tools were considered and have globally relied on the electron transfer(s) between the photosynthetic chain and a collecting electrode. In this context, we recently reported the implementation of an electrochemical set-up at the preparative scale to produce photocurrents from a Chlamydomonas reinhardtii algae suspension with an appropriate mediator (2,6-DCBQ) and a carbon gauze as the working electrode. In the present work, we wish to describe a mathematical modeling of the recorded photocurrents to better understand the effects of the experimental conditions on the photosynthetic extraction of electrons. In that way, we established a general model of an electrocatalytic mechanism at the preparative scale (that is, assuming a homogenous bulk solution at any time and a constant diffusion layer, both assumptions being valid under forced convection) in which the chemical step involves a Michaelis\textendashMenten-like behaviour. Dependences of transient and steady-state corresponding currents were analysed as a function of different parameters by means of zone diagrams. This model was tested to our experimental data related to photosynthesis. The corresponding results suggest that competitive pathways beyond photosynthetic harvesting alone should be taken into account. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In the past years, many strategies have been implemented to benefit from oxygenic photosynthesis to harvest photosynthetic electrons and produce a significant photocurrent. Therefore, electrochemical tools were considered and have globally relied on the electron transfer(s) between the photosynthetic chain and a collecting electrode. In this context, we recently reported the implementation of an electrochemical set-up at the preparative scale to produce photocurrents from a Chlamydomonas reinhardtii algae suspension with an appropriate mediator (2,6-DCBQ) and a carbon gauze as the working electrode. In the present work, we wish to describe a mathematical modeling of the recorded photocurrents to better understand the effects of the experimental conditions on the photosynthetic extraction of electrons. In that way, we established a general model of an electrocatalytic mechanism at the preparative scale (that is, assuming a homogenous bulk solution at any time and a constant diffusion layer, both assumptions being valid under forced convection) in which the chemical step involves a Michaelis–Menten-like behaviour. Dependences of transient and steady-state corresponding currents were analysed as a function of different parameters by means of zone diagrams. This model was tested to our experimental data related to photosynthesis. The corresponding results suggest that competitive pathways beyond photosynthetic harvesting alone should be taken into account. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim |
