showing 9 related works from this author
Enhancement of Electronic and Optical Properties of ZnO/Al2O3 Nanolaminate Coated Electrospun Nanofibers
2016
International audience; Nanolaminates are new class of promising nanomaterials with outstanding properties. Here we explored on the tuning of structural properties and the enhancement of electronic and optical properties of 1D PAN ZnO/Al2O3 nanolaminates designed by atomic layer deposition (ALD) and electrospinning. The influence of ZnO/Al2O3 bilayer thicknesses on the fundamental properties of 1D PAN ZnO/Al2O3 nanolaminates has been investigated. Due to the quantum confinement effect, the shift of XPS peaks to higher energies has been observed. Work function of Al2O3 was mostly independent of the bilayers number, whereas the ZnO work function decreased with an increase of the bilayer numbe…
Optical properties of ZnO deposited by atomic layer deposition (ALD) on Si nanowires
2018
International audience; In this work, we report proof-of-concept results on the synthesis of Si core/ ZnO shell nanowires (SiNWs/ZnO) by combining nanosphere lithography (NSL), metal assisted chemical etching (MACE) and atomic layer deposition (ALD). The structural properties of the SiNWs/ZnO nanostructures prepared were investigated by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies. The X-ray diffraction analysis revealed that all samples have a hexagonal wurtzite structure. The grain sizes are found to be in the range of 7-14 nm. The optical properties of the samples were investigated using reflectance and photoluminescence spectroscopy. The study o…
Impact of surface state on polyethylene glycol conformation confined inside a nanopore.
2021
Solid-state nanopores are a promising platform for characterizing proteins. In order to improve their lifetime and prevent fouling, Polyethylene Glycol (PEG) grafting is one of the most efficient and low-cost solutions. Different models to calculate the PEG thickness do not consider their interaction with the nanopore inner surface nor the effect of confinement. Here, we investigate by molecular dynamic simulation the PEG conformation inside a nanopore in the case of hydrophobic and hydrophilic nanopores. Our results reveal that the nanopore inner surface plays a role in the PEG organization and, thus, in the speed of the salt constituent. The resulting pair interaction between PEG and its …
Polynucleotide differentiation using hybrid solid-state nanopore functionalizing with α-hemolysin
2019
We report results from full atomistic molecular dynamics simulations on the properties of biomimetic nanopores. This latter result was obtained through the direct insertion of an α-hemolysin protein inside a hydrophobic solid-state nanopore. Upon translocation of different DNA strands, we demonstrate here that the theoretical system presents the same discrimination properties as the experimental one obtained previously. This opens an interesting way to promote the stability of a specific protein inside a solid nanopore to develop further biomimetic applications for DNA or protein sequencing.
Conical nanopores highlight the pro-aggregating effects of pyrimethanil fungicide on Aβ(1-42) peptides and dimeric splitting phenomena.
2022
International audience; The Aβ(1-42) aggregation is a key event in the physiopathology of Alzheimer's disease (AD). Exogenous factors such as environmental pollutants, and more particularly pesticides, can corrupt Aβ(1-42) assembly and could influence the occurrence and pathophysiology of AD. However, pesticide involvement in the early stages of Aβ(1-42) aggregation is still unknown. Here, we employed conical track-etched nanopore in order to analyse the Aβ(1-42) fibril formation in the presence of pyrimethanil, a widely used fungicide belonging to the anilinopyrimidine class. Our results evidenced a pro-aggregating effect of pyrimethanil on Aβ(1-42). Aβ(1-42) assemblies were successfully d…
Photoluminescence Study of Defects in ZnO-Coated Polyacrylonitrile Nanofibers
2020
International audience; Core-shell nanostructures of one-dimensional (1D) polyacrylonitrile (PAN)/zinc oxide (ZnO) were obtained by combining atomic layer deposition (ALD) and electrospinning. Nanofibers with different ZnO thicknesses were synthesized and investigated. The present work offers novel information about 1D ZnO structural defects and activation energies (Ea) by performing photoluminescence (PL) measurements. PL measurements of 1D ZnO/PAN samples were investigated from 77 K to 273 K (room temperature). By analyzing the obtained data of the emission spectrum, Ea and temperature coefficients were calculated. The results let us suggest an approximate model of defects in 1D ZnO/PAN s…
Conformation of Polyethylene Glycol inside Confined Space: Simulation and Experimental Approaches
2021
The modification of the inner nanopore wall by polymers is currently used to change the specific properties of the nanosystem. Among them, the polyethylene glycol (PEG) is the most used to prevent the fouling and ensure the wettability. However, its properties depend mainly on the chain structure that is very difficult to estimate inside this confined space. Combining experimental and simulation approaches, we provide an insight to the consequence of the PEG presence inside the nanopore on the nanopore properties. We show, in particular, that the cation type in the electrolyte, together with the type of electrolyte (water or urea), is at the origin of the ion transport modification in the n…
Natural payload delivery of the doxorubicin anticancer drug from boron nitride oxide nanosheets
2019
International audience; We studied the behavior of doxorubicin (DOX; an anticancer drug) molecules loaded on a boron nitride oxide nanosheet (BNO-NS) using the density functional theory (DFT), time-dependent density functional theory (TDDFT), and molecular dynamic (MD) simulation methods. We found that DOX molecules in pi-pi or covalent interaction with BNO-NS preserve their optical properties in water. Moreover, the BNO-NS vector allowed stabilizing the DOX molecules on a cellular membrane contrary to isolated DOX that randomly moved in the solvent box without any interaction with the cell membrane. From these results, we conclude that hydrophilic BNO-NS represents a good candidate for DOX…
Detection of Amyloid-β Fibrils Using Track-Etched Nanopores: Effect of Geometry and Crowding
2021
Several neurodegenerative diseases have been linked to proteins or peptides that are prone to aggregate in different brain regions. Aggregation of amyloid-β (Aβ) peptides is recognized as the main cause of Alzheimer's disease (AD) progression, leading to the formation of toxic Aβ oligomers and amyloid fibrils. The molecular mechanism of Aβ aggregation is complex and still not fully understood. Nanopore technology provides a new way to obtain kinetic and morphological aspects of Aβ aggregation at a single-molecule scale without labeling by detecting the electrochemical signal of the peptides when they pass through the hole. Here, we investigate the influence of nanoscale geometry (conical an…