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Research Group " BIONANO "
" Biomacromolecular Systems - Electron Transport at the Nanoscale"
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Home> Research Groups >
LEM "BIONANO"
The team is interested in the phenomenon of electron transport, coupled or not to enzymatic reactions, within nanoscale bioinspired systems integrating structures and biomimetic mechanisms. In particular, we seek to understand how the confinement and organization of redox biomolecules on the surface of nano-objects can modulate the efficiency of molecular recognition and enzymatic catalysis processes.
We seek to characterize these processes at the individual nano-object scale by means of mediator-tethered electrochemical microscopy (Mt/AFM-SECM), a functional imaging technique we invented. This local probe technique couples the electrochemical (SECM) and atomic force (AFM) microscopies into an original configuration where the redox species interrogated by the probe, "the mediator", is linked to the object to be imaged via a flexible chain. Mt/AFM-SECM microscopy is a state-of-the-art nano-electrochemical tool, one of the few that allows the electrochemical addressing of truly nanometric objects, and the only one capable of imaging of individual biomacromolecules.
Different original challenges are tackled, they have in common the need to develop new experimental strategies to allow unprecedented measurements at a nanometric scale.
The team's approach integrates the design and realization of molecular systems with bio-chains bearing redox probes, as well as the quantitative modeling of the functional properties of nano-systems.
Some of the team's current research topics are :
• Development of a single molecule array platform based on gold nanoarrays addressed by Mt/AFM-SECM microscopy.
• Mt/AFM-SECM microscopy complemented by the use of redox antibodies, as a new imaging tool for nano-bio-science: locating specific proteins on the surface of native viral particles.
• Exploring the catalytic activity of enzymatic systems confined on viral nanoparticles.
• Development of original instrumental strategies for the characterization of individual faradic events.
Keywords: Electrochemistry,
electron transport, cyclic volttametry, mediator-tethered atomic Force - electrochemical microscopy, Mt/ AFM-SECM, Tip-attached redox mediator, Tarm/ AFM-SECM, functional imaging, viral nanotechnology, redox nanoparticles, nanoscale biostructures, virus nanocarriers, enzymes, enzymatic cascade, molecular recognition, modeling transport phenomena
.
Press Highlights:
2004 Anal.
Chem. ; 2015 JPK News
Other specific savoir-faire: Assembling
of organized enzymatic systems at electrode surfaces by
immunological reactions. Quantitative characterization
of their catalytic behavior. Dynamics of short DNA on electrode surfaces. |
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 Savoir-Faire, Expertise of the group ------------------------------------------------------------------------------------------------------------------ |
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Development of Electrochemical-Atomic Force Microscopies AFM-SECM |
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An
experimental set-up, combining the imaging
capabilities of Atomic Force (AFM) and of Electrochemical
Microscopy (SECM) has been assembled. This required
the development of a novel method for fabricating gold ultra-electrodes of submicrometer dimension,
of well defined geometry, that could be used
as combined AFM-SECM probes. We recently finalized the development of the imaging mode in two configurations : the Mt (Molecule-touching) /AFM-SECM aimed to single redox-macromolecule resolution, and the Tarm (for tip-attached redox mediators) AFM-SECM aimed to observe enzyme functioning.
 Publications - selection : ACS Nano 2015, 7, 4151 Abstract - ACS Nano 2013, 7, 4151 Abstract - Anal. Chem. 2011, 83, 7924 Abstract - Anal. Chem. 2010, 82, 6353 Abstract - ACS Nano 2009, 3, 2927 Abstract - ACS Nano 2009, 3, 819 Abstract - J. Phys. Chem. B 2007, 111, 6051 Abstract - J. Am. Chem. Soc. 2004, 126, 10095 Abstract -: Anal.
Chem. 2003, 74, 6355 Abstract
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Revealing Phenomena using Cyclic Voltammetry CV |
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Making use of
the fast scan rate (kV/s) CV
technique, originally developped in this laboratory,
the rigidification of short DNA oligomers
(20 bp), end-grafted to a
gold electrode surface, upon their hybridization
by unlabeled complementary strands present
in solution, was demonstrated for the first time by our group. Recently, we demonstrated that, once optimized, electrode attached redox-peptide systems uniquely allow in-situ real-time CV monitoring of the action of proteases, and unraveled a specific and totally unexpected behavior of thrombin action (redox peptides created with Biopep spin-off (Horiba Medical France).
Publications: Langmuir 2012, 28, 8804 (peptide/thrombine) Abstract - Langmuir 2010, 26, 10347 (peptide/thrombine) Abstract - J. Am. Chem. Soc. 2003, 125, 1112 (ss/ds DNA) Abstract |
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Modeling the dynamics of polymeric biochains / the kinetic action of enzymes at interfaces |
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Our
ability to model the motional dynamics of
the redox heads of surface end-grafted semi-rigid
polymeric chains allows the quantitative
study of sequence-dependent DNA rigidification
caused by hybridization. The group also models the kinetics of enzyme action on surface-attached aubstrates , delivering in Langmuir 2012 "A practical guide to progress curve analysis in any kinetic situation"
Publications - selection: Langmuir 2012, 28, 14665 (enzyme action) Abstract - J. Am. Chem. Soc. 2008, 130, 9812 Abstract - J. Am. Chem. Soc. 2006, 128 , 542 Abstract |
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Redox Functionalization : Enzymatic
3'- redox end-labeling of DNA |
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A unique
ferrocene-2',3'-dideoxynucleotide compound
has been synthetized for enzymatic 3'-redox mono-end-labeling of single-stranded
DNA with terminal deoxynucleotidyl transferase
(TDT).
TDT enzymatic incorporation of the ferrocene label in homogeneous phase which
can be extended to end-grafted
DNA monolayers on surfaces. The high efficiency
of this elegant and universallabeling technique makes
it particurlaly suitable for DNA chips technology.
Publications : J. Am. Chem. Soc. 2007, 129 - 2735, Abstract Bioconjugate Chem. 2001, 12, 396, Abstract |
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 last
modified: november
2017 |
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