Search results for "force microscopy"
showing 10 items of 247 documents
A mucosal pellicle modifies the physical properties of epithelial
2017
International audience
International Scanning Probe Microscopy Conference
2016
International audience
Technological innovation around protein and cell biochip for diagnosis: a translational research from nanoworld to patient
2009
International audience; A great challenge in biosensors and diagnosis devices relies on the way to reconstitute relevant biological mechanisms on surface of the biochips and which analytical tools are convenient to provide accurate and rapid information on the structures and function of molecules attached to this surface. A better control in the realization of biochips can be obtained in combining different complementary approaches while always keeping in mind the biological key point. Researches in CLIPP are focused towards this objective. Conception, realization and characterization of protein and cell chips are presented. We detail different strategies of materials engineering1,2,3, chem…
Cell imaging connected with protein mapping to investigate glyphosate induced toxicity on human keratinocytes
2009
During the skin ageing which is accelerated by environmental factors, the generated reactive oxygen species make unstable the "proliferation/differentiation/apoptosis" coupling of epidermal cells. A biochemical study, previously realized on human keratinocyte cultures treated by a pesticide, glyphosate, allowed the validation of an in vitro model of skin ageing. In this work, we propose to study the loss of HaCaT cell integrity appearing after this chemical induced-oxidative stress. An original approach, combining a micro- to nanoscale cell characterization and analysis of fluctuating protein expression, is proposed: a) the exploration of cell growth and morphology through fluorescence and …
Etude dynamique et structurale de biomolécules par microscopie à force atomique HS-AFM : application à une petite protéine de choc thermique sHsp
2012
The atomic force microscopy (AFM) gives access to the topography of organic and inorganic samplesat the atomic scale. The latest innovations offer the possiblity to understand the sample nano-mechanicalproperties (elasticity, adhesion...). Its feature set allows overcoming the demands of nanotechnology,both in the fields of physics, chemistry and biology.However, understanding biological processes require faster acquisitions for the atomic forcemicroscopy, less than a second per frame. As conventional equipment does not offer the possibility toovercome the constraint of time for dynamical studies, a prototype of high-speed atomic forcemicroscope (HS-AFM) was developed in partnership with Pr…
Carbon Dots Dispersed on Graphene/SiO2/Si: A Morphological Study
2019
Low-dimensional carbon materials occupy a relevant role in the field of nanotechnology. Herein, the authors report a study conducted by atomic force microscopy and Raman spectroscopy on the deposition of carbon dots onto graphene surfaces. The study aims at understanding if and how the morphology and the microstructure of chemical vapor deposited graphene on Si/SiO2 may change due to the interaction with the carbon dots. Potential alteration in the graphene's electrical properties might be detrimental for optoelectronic applications. The deposition of carbon dots dispersed in water and ethanol solvents are explored to investigate the effect of solvents with different fluidic properties. The…
Force measurements and tip shape approximation with the atomic force microscope
2011
The Atomic Force Microscope (AFM) is an instrument with huge impact on modern research in the nanosciences and in nanotechnology. In AFM, a tip which is sharp on a scale of nanometers or tens of nanometers, is scanning along the surface which is imaged. A few among the large numbers of factors that potentially affect the interaction between the tip and the surface were studied in the experimental work that form this Thesis. Friction and elasticity measurements with AFM and the approximation of the tip shape are discussed. Also the contribution of the imaging environment is studied. A commercial AFM was modified into a so called environmental-AFM (env- AFM) , where the imaging conditions, su…
On-Surface Synthesis of Oligo(indenoindene)
2020
Fully conjugated ladder polymers (CLP) possess unique optical and electronic properties, and are considered promis-ing materials for applications in (opto)electronic devices. Poly(indenoindene) is a CLP consisting of an alternating array of five- and six-membered rings, which has remained elusive so far. Here, we report an on-surface synthesis of oligo(indenoindene) on Au(111). Its structure and a low elec-tronic bandgap have been elucidated by low-temperature scanning tunneling microscopy and spectroscopy and non-contact atomic force microscopy, complemented by density functional theory calculations. Achieving defect-free seg-ments of oligo(indenoindene) offers an exclusive insight into th…
Redox Materials by the Covalent Entrapment of Redox-Active Dirhodium(II,II) Species in a Siloxane Network
2004
Hydrolysis and polycondensation of the coupling agent (aminopropyl)triethoxysilane (APS), axially coordinated to the redox-active complex [Rh 2 (form) 2 (CH 3 COO) 2 -(APS) 2 ], lead to the insertion of redox-active inorganic microdomains into a siloxane network; the new polymers undergo cyclic redox reactions indicating that dirhodium(II,II) centres retain their redox activity even when incorporated into siloxane networks.
Micropatterning of neurons using organic substrates in culture
1997
Abstract In this study, we have used spatially defined surfaces of organic thin films to micropattern the outgrowth of central nervous system neurons in culture. Glass substrates were first chemically modified with synthetic peptides derived from an extra-cellular matrix protein laminin to couple a functionality that promotes a neuron-substrate interaction. The modification procedure was verified using X-ray photoelectron spectroscopy. The functionality of the modified glass surfaces was examined by growing neurons dissociated from mammalian central nervous tissues in culture. Spatially defined surfaces of the peptide were then fabricated by selectively attaching the peptide to coplanar sur…