Search results for "Biomolecule"
showing 10 items of 666 documents
Micro- to Nanoscale Bio-Hybrid Hydrogels Engineered by Ionizing Radiation
2021
Bio-hybrid hydrogels consist of a water-swollen hydrophilic polymer network encapsulating or conjugating single biomolecules, or larger and more complex biological constructs like whole cells. By modulating at least one dimension of the hydrogel system at the micro- or nanoscale, the activity of the biological component can be extremely upgraded with clear advantages for the development of therapeutic or diagnostic micro- and nano-devices. Gamma or e-beam irradiation of polymers allow a good control of the chemistry at the micro-/nanoscale with minimal recourse to toxic reactants and solvents. Another potential advantage is to obtain simultaneous sterilization when the absorbed doses are wi…
Monte Carlo analysis of polymer translocation with deterministic and noisy electric fields
2012
AbstractPolymer translocation through the nanochannel is studied by means of a Monte Carlo approach, in the presence of a static or oscillating external electric voltage. The polymer is described as a chain molecule according to the two-dimensional “bond fluctuation model”. It moves through a piecewise linear channel, which mimics a nanopore in a biological membrane. The monomers of the chain interact with the walls of the channel, modelled as a reflecting barrier. We analyze the polymer dynamics, concentrating on the translocation time through the channel, when an external electric field is applied. By introducing a source of coloured noise, we analyze the effect of correlated random fluct…
Conformational Changes and Charge Transfer in Biomolecules Resolved Using Dynamic Enhanced Raman Correlation Spectroscopy
2019
International audience; In this contribution, we report that conforma-tional changes of molecules that are often buried in a wide-distributed Gaussian distribution can be discerned by analyzing the dynamics of specific Raman lines. We investigate the pertinence of the auto-and cross-correlation functions applied to the dynamics of three Raman lines of an amino acid, the tryptophan. The cross-correlation between intensity and the Raman band is an indicator of the charge transfer during the diffusion limited reaction of tryptophan and the gold surface. The Pećlet number Pe can provide a valuable indicator of the convective and/or diffusive features of each Raman band. Adsorption induced confo…
Multifunctional clickable and protein-repellent magnetic silica nanoparticles
2016
Silica nanoparticles are versatile materials whose physicochemical surface properties can be precisely adjusted. Because it is possible to combine several functionalities in a single carrier, silica-based materials are excellent candidates for biomedical applications. However, the functionality of the nanoparticles can get lost upon exposure to biological media due to uncontrolled biomolecule adsorption. Therefore, it is important to develop strategies that reduce non-specific protein-particle interactions without losing the introduced surface functionality. Herein, organosilane chemistry is employed to produce magnetic silica nanoparticles bearing differing amounts of amino and alkene func…
A first peek into sub-picosecond dynamics of spin energy levels in magnetic biomolecules
2019
We estimate the time- and temperature-evolution of spin energy levels in a metallopeptide by combining molecular dynamics with crystal field analysis. Fluctuations of tens of cm-1 for spin energy levels at fs times gradually average out at longer times. We confirm that local vibrations are key in spin dynamics.
Hybrid Inorganic‐Organic White Light Emitting Diodes
2020
This chapter reviews the state of the art of materials, technologies, characterizations, process and challenges concerning hybrid white light‐emitting diodes (LEDs). Here, for a “hybrid LED” we mean a device based on a layer of organic phosphors (or a mix of inorganic and organic ones) pumped by a high‐energy inorganic LED. Light is emitted by a frequency down‐conversion (sometimes simply named color‐conversion) process. Benefits and weak spots of this technology are investigated with a special attention for the materials involved into the process of frequency down‐conversion, in order to envisage the future impact of the hybrid lighting technology among the well‐established inorganic ones.
Self-assembled FeCo/gelatin nanospheres with rapid magnetic response and high biomolecule-loading capacity.
2009
Carbon nanotubes as gene carriers: Focus on internalization pathways related to functionalization and properties
2017
Abstract Carbon nanotubes represent promising transporters for delivery of DNA and other biomolecules into living cells. Various methods of CNTs surface functionalization have been developed. These are essential to improve CNTs dispersibility and permit their interactions with biological structures that broaden their use in advanced biomedical applications. The present review discusses the different single walled carbon nanotubes and multiwalled carbon nanotubes functionalization methods, leading to the formation of optimized and functionalized-CNT complexes with DNA. F-CNTs are recognized as efficient and promising gene carriers. Emphasis is then placed on the processes used by f-CNTs/DNA …
A DNA-nanoparticle actuator enabling optical monitoring of nanoscale movements induced by an electric field.
2018
Merging biological and non-biological matter to fabricate nanoscale assemblies with controllable motion and function is of great interest due to its potential application, for example, in diagnostics and biosensing. Here, we have constructed a DNA-based bionanoactuator that interfaces with biological and non-biological matter via an electric field in a reversibly controllable fashion. The read-out of the actuator is based on motion-induced changes in the plasmon resonance of a gold nanoparticle immobilized to a gold surface by single stranded DNA. The motion of the gold nanoparticle and thus the conformational changes of the DNA under varying electric field were analyzed by dark field spect…
Conformal invariance of the writhe of a knot
2008
We give a new proof of an old theorem by Banchoff and White 1975 that claims that the writhe of a knot is conformally invariant.