scholarly journals AFM and FTIR Investigation of the Effect of Water Flow on Horseradish Peroxidase

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 306
Author(s):  
Yuri D. Ivanov ◽  
Tatyana O. Pleshakova ◽  
Ivan D. Shumov ◽  
Andrey F. Kozlov ◽  
Anastasia A. Valueva ◽  
...  
Keyword(s):  
Horseradish Peroxidase ◽  
Enzymatic Activity ◽  
Substrate Surface ◽  
Solid Substrate ◽  
Attenuated Total Reflection ◽  
Flow Section ◽  
Force Microscopy ◽  
Atomic Force ◽  
Influence Of Water ◽  
Actual Direction

Atomic force microscopy (AFM)-based fishing is a promising method for the detection of low-abundant proteins. This method is based on the capturing of the target proteins from the analyzed solution onto a solid substrate, with subsequent counting of the captured protein molecules on the substrate surface by AFM. Protein adsorption onto the substrate surface represents one of the key factors determining the capturing efficiency. Accordingly, studying the factors influencing the protein adsorbability onto the substrate surface represents an actual direction in biomedical research. Herein, the influence of water motion in a flow-based system on the protein adsorbability and on its enzymatic activity has been studied with an example of horseradish peroxidase (HRP) enzyme by AFM, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and conventional spectrophotometry. In the experiments, HRP solution was incubated in a setup modeling the flow section of a biosensor communication. The measuring cell with the protein solution was placed near a coiled silicone pipe, through which water was pumped. The adsorbability of the protein onto the surface of the mica substrate has been studied by AFM. It has been demonstrated that incubation of the HRP solution near the coiled silicone pipe with flowing water leads to an increase in its adsorbability onto mica. This is accompanied by a change in the enzyme’s secondary structure, as has been revealed by ATR-FTIR. At the same time, its enzymatic activity remains unchanged. The results reported herein can be useful in the development of models describing the influence of liquid flow on the properties of enzymes and other proteins. The latter is particularly important for the development of biosensors for biomedical applications—particularly for serological analysis, which is intended for the early diagnosis of various types of cancer and infectious diseases. Our results should also be taken into account in studies of the effects of protein aggregation on hemodynamics, which plays a key role in human body functioning.

scholarly journals AFM Study of the Influence of Glycerol Flow on Horseradish Peroxidase near the in/out Linear Sections of a Coil

2021 ◽  
Vol 11 (4) ◽  
pp. 1723
Author(s):  
Yuri D. Ivanov ◽  
Tatyana O. Pleshakova ◽  
Ivan D. Shumov ◽  
Andrey F. Kozlov ◽  
Irina A. Ivanova ◽  
...  
Keyword(s):  
Horseradish Peroxidase ◽  
Enzymatic Activity ◽  
Protein Adsorption ◽  
Substrate Surface ◽  
Control Sample ◽  
Thermal Stabilization ◽  
Heat Transfer Fluid ◽  
Force Microscopy ◽  
Model Protein ◽  
Linear Sections

Flow-based coiled systems, through which a heat transfer fluid (such as glycerol) is pumped, are widely used for thermal stabilization of bioreactors and biosensor cuvettes and cells. Previously, using horseradish peroxidase (HRP) as a model protein, we have demonstrated that the incubation of a protein solution in a flow-based system over coiled pipe with flowing glycerol leads to a change in the adsorption properties of the protein macromolecules. Herein, we have studied the effect of the glycerol flow on the properties of HRP, the solution of which was placed differently: i.e., near either the inflow or the outflow linear sections of the pipe, while the coiled section of the pipe was shielded with a grounded metallic cover. Atomic force microscopy (AFM) has been employed in order to visualize the HRP protein macromolecules adsorbed from its solution onto the mica substrate surface. The quantity of adsorbed protein was estimated based on the AFM data. The enzymatic activity of HRP was estimated by spectrophotometry. We demonstrate that a change in the properties of HRP enzyme was observed after the incubation of its solution near the inflow/outflow linear sections of the pipe with flowing glycerol. Namely, after the incubation of HRP solution near the inflow section, a decrease in the protein adsorption onto mica was observed, but its enzymatic activity remained unchanged in comparison to the control sample. In another case, when the HRP solution was incubated near the outflow section, an increased protein adsorption was observed, while the enzyme exhibited considerably lower activity.

scholarly journals Investigation of the Influence of Liquid Motion in a Flow-based System on an Enzyme Aggregation State with an Atomic Force Microscopy Sensor: The Effect of Water Flow

2020 ◽  
Vol 10 (13) ◽  
pp. 4560 ◽  
Author(s):  
Yuri D. Ivanov ◽  
Tatyana O. Pleshakova ◽  
Ivan D. Shumov ◽  
Andrey F. Kozlov ◽  
Tatyana S. Romanova ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Enzymatic Activity ◽  
Liquid Flow ◽  
Flow Section ◽  
Liquid Motion ◽  
Aggregation State ◽  
Measuring Cell ◽  
Force Microscopy ◽  
Atomic Force ◽  
Solution Studies

The influence of liquid motion in flow-based systems on the aggregation state of an enzyme and on its enzymatic activity was studied, with horseradish peroxidase (HRP) as an example. Our experiments were carried out in a setup modeling the flow section of the biosensor communication with a measuring cell containing a protein solution. Studies were conducted for a biosensor measuring cell located along the axis of a spiral-moving liquid flow. The aggregation state of the protein was determined with an atomic force microscopy-based sensor (AFM sensor). It has been demonstrated that upon flowing of water through silicone biosensor communications, an increased aggregation of HRP protein was observed, but, at the same time, its enzymatic activity did not change. Our results obtained herein are useful in the development of models describing the influence of liquid flow in biosensor communications on the properties of enzymes and other proteins. This is particularly important for the development of serologic protein biosensors, which are beginning to be used for the early diagnosis of oncological diseases (such as brain cancer, prostate cancer, breast cancer etc.). The results obtained herein should also be taken into account when considering possible changes in hemodynamics due to increased protein aggregation.

scholarly journals Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 878
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Ft Ir ◽  
Acrylate Monomers ◽  
Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

A Novel Cell Co-Culture Method Utilizing Thermo-Responsive Surface

2007 ◽  
Vol 342-343 ◽  
pp. 221-224
Author(s):  
Jin Suk Bae ◽  
Ga Young Jun ◽  
Akihiko Kikuchi ◽  
Teruo Okano ◽  
Chang Hyun Ahn ◽  
...  
Keyword(s):  
Contact Angle ◽  
Electron Spectroscopy ◽  
Electron Beam Irradiation ◽  
Culture Method ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Beam Irradiation ◽  
Cover Glass ◽  
Force Microscopy ◽  
Atomic Force

In this work, we developed a novel patterned co-culture method with thermo-responsive poly(N-isopropylacrylamide) (PIPAAm) and poly(N-ρ-vinylbenzyl-Ο-β-D-galactopyranosyl-(1→ 4)-D-gluconamide) (PVLA) inducing active hepatocyte attachment. Patterned graft of PIPAAm onto PS dishes was carried out by electron beam irradiation using cover-glass as a photomask. PVLA was only coated onto PIPAAm-ungrafted domain because of hydrated hydrophilic property of PIPAAm at below the LCST. Analysis by attenuated total reflection-Fourier transform infrared and electron spectroscopy for chemical analysis revealed that PIPAAm and PVLA were successfully grafted and coated on surfaces of PS dishes. PIPAAm-grafted surface exhibited decreasing contact angle by changing temperature from 37 to 20°C, while PVLA-coated PS and non-treated PS had negligible contact angle changes with temperature alternation. Atomic force microscopy (AFM) results showed that PIPAAm-grafted and PVLA-coated PS had smoother surfaces than that of ungrafted PS dishes. After culture for 12 hours, hepatocytes were well attached on PVLA-coated domain. Hepatocytes adherent on PIPAAm-grafted domain were detached by decreasing temperature. And then, fibroblasts were seeded onto PIPAAm pattern-grafted domain. Fibroblasts were only attached and spread onto PIPAAm-grafted domain. Co-cultured hepatocytes showed better differentiated function of albumin expression compared to homotypic hepatocyte culture

scholarly journals Growth of Ordered Graphene Ribbons by Sublimation Epitaxy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 449
Author(s):  
Shuxian Cai ◽  
Xingfang Liu ◽  
Xin Zheng ◽  
Zhonghua Liu
Keyword(s):  
Substrate Surface ◽  
Graphene Film ◽  
Graphene Ribbon ◽  
High Quality ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Few Layer Graphene

Ordered graphene ribbons were grown on the surface of 4° off-axis 4H-SiC wafers by sublimation epitaxy, and characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman spectroscopy (μ-Raman). SEM showed that there were gray and dark ribbons on the substrate surface, and AFM further revealed that these ordered graphene ribbons had clear stepped morphologies due to surface step-bunching. It was shown by μ-Raman that the numbers of graphene layers of these two types of regions were different. The gray region was composed of mono- or bilayer ordered graphene ribbon, while the dark region was of tri- or few-layer ribbon. Meanwhile, ribbons were all homogeneous and had a width up to 40 μm and a length up to 1000 μm, without micro defects such as grain boundaries, ridges, or mono- and few-layer graphene mixtures. The results of this study are useful for optimized growth of high-quality graphene film on silicon carbide crystal.

scholarly journals Surface Morphology of Single and Multi-Layer Silicon Nitride Dielectric Nano-Coatings on Silicon Dioxide and Polycrystalline Silicon

2019 ◽  
Vol 26 (1) ◽  
pp. 25-29
Author(s):  
Liga AVOTINA ◽  
Elina PAJUSTE ◽  
Marina ROMANOVA ◽  
Gennady ENICHEK ◽  
Aleksandrs ZASLAVSKIS ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Surface Morphology ◽  
Polycrystalline Silicon ◽  
Chemical Vapour ◽  
Attenuated Total Reflection ◽  
Infrared Spectrometry ◽  
Chemical Bonds ◽  
Force Microscopy ◽  
Atomic Force ◽  
Pressure Chemical

Silicon nitride (Si3N4) in a form of single and multi-layer nanofilms is proposed to be used as a dielectric layer in nanocapacitors for operation in harsh environmental conditions. Characterization of surface morphology, roughness and chemical bonds of the Si3N4 coatings has an important role in production process as the surface morphology affects the contact surface with other components of the produced device. Si3N4 was synthesized by using low pressure chemical vapour deposition method and depositing single and multi-layer (3 – 5 layers) nanofilms on SiO2 and polycrystalline silicon (PolySi). The total thickness of the synthesized nanofilms was 20 – 60 nm. Surface morphology was investigated by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical bonds in the layers were identified by means of Fourier transform infrared spectrometry, attenuated total reflection (FTIR-ATR) method. (From the SEM and AFM images it was estimated that both single and multi-layer coatings are deposited homogenously. Si-N breathing and stretching modes are observed in FTIR spectra and the surface morphology is highly dependent on PolySi, therefore suggesting the decrease of the roughness of the bottom electrode for use in the nanocapacitors.

scholarly journals Poly(furfuryl alcohol)-Polycaprolactone Blends

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1069 ◽  
Author(s):  
Gabriele Nanni ◽  
José A. Heredia-Guerrero ◽  
Uttam C. Paul ◽  
Silvia Dante ◽  
Gianvito Caputo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Furfuryl Alcohol ◽  
Barrier Properties ◽  
Tensile Tests ◽  
Attenuated Total Reflection ◽  
Toxicity Tests ◽  
Scanning Calorimetry ◽  
Blend Films ◽  
Force Microscopy ◽  
Atomic Force

Poly(furfuryl alcohol) (PFA) is a bioresin synthesized from furfuryl alcohol (FA) that is derived from renewable saccharide-rich biomass. In this study, we compounded this bioresin with polycaprolactone (PCL) for the first time, introducing new functional polymer blends. Although PCL is biodegradable, its production relies on petroleum precursors such as cyclohexanone oils. With the method proposed herein, this dependence on petroleum-derived precursors/monomers is reduced by using PFA without significantly modifying some important properties of the PCL. Polymer blend films were produced by simple solvent casting. The blends were characterized in terms of surface topography by atomic force microscopy (AFM), chemical interactions between PCL and PFA by attenuated total reflection-Fourier transform infrared (ATR-FTIR), crystallinity by XRD, thermal properties by differential scanning calorimetry (DSC), and mechanical properties by tensile tests and biocompatibility by direct and indirect toxicity tests. PFA was found to improve the gas barrier properties of PCL without compromising its mechanical properties, and it demonstrated sustained antioxidant effect with excellent biocompatibility. Our results indicate that these new blends can be potentially used in diverse applications ranging from food packing to biomedical devices.

scholarly journals Epitaxial Order Driven by Surface Corrugation: Quinquephenyl Crystals on a Cu(110)-(2×1)O Surface

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 373 ◽  
Author(s):  
Roland Resel ◽  
Markus Koini ◽  
Jiri Novak ◽  
Steven Berkebile ◽  
Georg Koller ◽  
...  
Keyword(s):  
Thin Film ◽  
Crystal Surface ◽  
Substrate Surface ◽  
Lattice Misfit ◽  
Crystallographic Structure ◽  
Initial Growth ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Lattice Matching ◽  
Atomic Force

A 30 nm thick quinquephenyl (5P) film was grown by molecular beam deposition on a Cu(110)(2×1)O single crystal surface. The thin film morphology was studied by light microscopy and atomic force microscopy and the crystallographic structure of the thin film was investigated by X-ray diffraction methods. The 5P molecules crystallise epitaxially with (201)5P parallel to the substrate surface (110)Cu and with their long molecular axes parallel to [001]Cu. The observed epitaxial alignment cannot be explained by lattice matching calculations. Although a clear minimum in the lattice misfit exists, it is not adapted by the epitaxial growth of 5P crystals. Instead the formation of epitaxially oriented crystallites is determined by atomic corrugations of the substrate surface, such that the initially adsorbed 5P molecules fill with its rod-like shape the periodic grooves of the substrate. Subsequent crystal growth follows the orientation and alignment of the molecules taken within the initial growth stage.

Combined in situ atomic force microscopy and infrared attenuated total reflection spectroelectrochemistry

The Analyst ◽  
2013 ◽  
Vol 138 (22) ◽  
pp. 6746 ◽  
Author(s):  
Daniel Neubauer ◽  
Jochen Scharpf ◽  
Alberto Pasquarelli ◽  
Boris Mizaikoff ◽  
Christine Kranz
Keyword(s):  
Atomic Force Microscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Force Microscopy ◽  
Atomic Force
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