scholarly journals Synthesis and Surface Modification of Nanostructured F-Doped ZnO: Toward a Transducer for Label-Free Optical Biosensing

2019 ◽  
Vol 9 (16) ◽  
pp. 3380 ◽  
Author(s):  
Giovanna Chianese ◽  
Monica Terracciano ◽  
Rosalba Moretta ◽  
Paolo Cappiello ◽  
Giuseppe Vitiello ◽  
...  
Keyword(s):  
Surface Modification ◽  
Protein A ◽  
Analytical Techniques ◽  
Label Free ◽  
Water Contact ◽  
Optical Biosensing ◽  
Doped Zno ◽  
Spectroscopic Reflectometry ◽  
Chemical Procedure ◽  
Contact Angle Analysis

In this work, the surface of nanostructured fluorine-doped ZnO (nZnO·F) is functionalized with protein A (PrA), and used as a model biomolecule. The chemical procedure is characterized by several analytical techniques such as Fourier Transform Infrared Spectroscopy, water contact angle analysis, and fluorescence microscopy. The surface modification of nZnO·F by binding increasing concentrations of PrA is also investigated by two label-free optical techniques, i.e., the spectroscopic reflectometry and the steady-state photoluminescence. The results are compared with those obtained using undoped nZnO substrates in order to highlight the better performances of nZnO·F due to the fluorine doping. The results of this study pave the way for the design and realization of a ZnO-based nanostructured platform for label-free optical sensing.

scholarly journals Label-Free Optical Biosensing Using Low-Cost Electrospun Polymeric Nanofibers

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 119
Author(s):  
Paula Martínez-Pérez ◽  
Salvador Ponce-Alcántara ◽  
Nieves Murillo ◽  
Ana Pérez-Márquez ◽  
Jon Maudes ◽  
...  
Keyword(s):  
Real Time ◽  
Large Scale ◽  
High Surface ◽  
Protein A ◽  
Volume Ratio ◽  
Polyamide 6 ◽  
Optical Biosensor ◽  
Label Free ◽  
Electrospinning Technique ◽  
Optical Biosensing

Polymeric nanofiber matrices are promising structures to develop biosensing devices due to their easy and affordable large-scale fabrication and their high surface-to-volume ratio. In this work, the suitability of a polyamide 6 nanofiber matrix for the development of a label-free and real-time Fabry–Pérot cavity-based optical biosensor was studied. For such aim, in-flow biofunctionalization of nanofibers with antibodies, bound through a protein A/G layer, and specific biodetection of 10 µg/mL bovine serum albumin (BSA) were carried out. Both processes were successfully monitored via reflectivity measurements in real-time without labels and their reproducibility was demonstrated when different polymeric nanofiber matrices from the same electrospinning batch were employed as transducers. These results demonstrate not only the suitability of correctly biofunctionalized polyamide 6 nanofiber matrices to be employed for real-time and label-free specific biodetection purposes, but also the potential of electrospinning technique to create affordable and easy-to-fabricate at large scale optical transducers with a reproducible performance.

scholarly journals Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrzej Sikora ◽  
Dariusz Czylkowski ◽  
Bartosz Hrycak ◽  
Magdalena Moczała-Dusanowska ◽  
Marcin Łapiński ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Chemical Composition ◽  
Water Contact Angle ◽  
Plasma Sheet ◽  
Atmospheric Pressure ◽  
Argon Plasma ◽  
Fullerene Derivative ◽  
Water Contact ◽  
Pmma Polymer

AbstractThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number of plasma scans (up to 3) and, the kind of treated material. In order to assess the plasma effect, the possible changes in the wettability, roughness, chemical composition, and mechanical properties of the plasma-treated samples’ surfaces were evaluated by water contact angle goniometry (WCA), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The best result concerning the water contact angle reduction was from 83° to 29.7° for the PMMA material. The ageing studies of the PMMA plasma-modified surface showed long term (100 h) improved wettability. As a result of plasma treating, changes in the samples surface roughness parameters were observed, however their dependence on the number of plasma scans is irregular. The ATR-FTIR spectra of the PMMA plasma-treated surfaces showed only slight changes in comparison with the spectra of an untreated sample. The more significant differences were demonstrated by XPS measurements indicating the surface chemical composition changes after plasma treatment and revealing the oxygen to carbon ratio increase from 0.1 to 0.4.

Magnetic Nanoparticles Derivatized with Dual Functional Groups for Environmental Applications

2010 ◽  
Vol 148-149 ◽  
pp. 949-952
Author(s):  
Hai Bo He ◽  
Qing Zhong Guo
Keyword(s):  
Magnetic Nanoparticles ◽  
Environmental Remediation ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
Water Contact ◽  
Dual Functional ◽  
New Material ◽  
Ft Ir ◽  
Contact Angle Analysis ◽  
Effective Sorbent

In this study, the magnetic nanoparticles derivatized with dual functional moieties of dodecyl and mercapto were prepared, which characterized by X-ray diffraction (XRD), scanning electron microscope(SEM), surface area and pore size determination, fourier transform infrared spectrometry (FT-IR) and water contact angle analysis. The new material was proved to be an effective sorbent for environmental remediation.

scholarly journals Commentary on Ivancic et al.: Enzyme kinetics from circular dichroism of insulin reveals mechanistic insights into the regulation of insulin-degrading enzyme

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Giuseppe Grasso
Keyword(s):  
Analytical Techniques ◽  
Label Free ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Analytical Technique ◽  
Biochemical Pathways ◽  
New Methods ◽  
The World ◽  
Free Environment ◽  
Enormous Number

Despite the enormous number of therapeutic advances in medicine, nowadays many diseases are still incurable, mainly due to the lack of knowledge of the pathological biochemical pathways triggering those diseases. For this reason, it is compulsory for the scientific community to investigate and unveil the biomolecular mechanisms responsible for the development of those diseases, such as Alzheimer’s disease and diabetes, which are widespread all over the world. In this scenario, it is of paramount importance to develop new analytical techniques and experimental procedures that are capable to make the above-mentioned investigations feasible. These new methods should allow easy performable analysis carried out in a label-free environment, in order to give reliable answers to specific biochemical questions. A recent paper published on Bioscience Reports by Ivancic et al. (https://doi.org/10.1042/BSR20181416) proposes a new analytical technique capable to reveal some mechanistic insights into the regulation of insulin-degrading enzyme (IDE), a protein involved in the above-mentioned diseases. IDE is a multifaceted enzyme having different and not well-defined roles in the cell, but it is primarily a proteolytic enzyme capable to degrade several different amyloidogenic substrates involved in different diseases. Moreover, many molecules are responsible for IDE activity modulation so that understanding how IDE activity is regulated represents a very challenging analytical task. The new analytical approach proposed by Ivancic et al. reports on the possibility to study IDE activity in an unbiased and label-free manner, representing a valid alternative assay for the investigation of any proteases degradative activity.

scholarly journals Design of an Aluminum/Polymer Plasmonic 2D Crystal for Label-Free Optical Biosensing

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3335
Author(s):  
Luca Tramarin ◽  
Carlos Angulo Barrios
Keyword(s):  
Surface Plasmon Polariton ◽  
Design Parameters ◽  
Device Performance ◽  
Label Free ◽  
Multi Objective Optimization ◽  
Optical Biosensing ◽  
Plasmonic Crystal ◽  
Fdtd Simulations ◽  
Points Of View ◽  
Difference Time

A design study of a nanostructured two-dimensional plasmonic crystal based on aluminum and polymeric material for label-free optical biosensing is presented. The structure is formed of Al nanohole and nanodisk array layers physically separated by a polymeric film. The photonic configuration was analyzed through finite-difference time-domain (FDTD) simulations. The calculated spectral reflectance of the device exhibits a surface plasmon polariton (SPP) resonance feature sensitive to the presence of a modeled biolayer adhered onto the metal surfaces. Simulations also reveal that the Al disks suppress an undesired SPP resonance, improving the device performance in terms of resolution as compared to that of a similar configuration without Al disks. On the basis of manufacturability issues, nanohole diameter and depth were considered as design parameters, and a multi-objective optimization process was employed to determine the optimum dimensional values from both performance and fabrication points of view. The effect of Al oxidation, which is expected to occur in an actual device, was also studied.

scholarly journals Hydrophobic Waxes in Ivory Nuts Affect Surface Modification by Atmospheric Air Plasma Jet

2020 ◽  
Vol 2 (2) ◽  
pp. 48-49
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Water Contact Angle ◽  
Plasma Jet ◽  
Raman Imaging ◽  
Wall Material ◽  
Air Plasma ◽  
Water Contact ◽  
Atmospheric Air ◽  
Imaging Results

Ivory nuts, produced by palms from the genus Phytelephas, possess a hard and microporous endosperm with a strong resemblance to elephant ivory. The nuts sustainable appeal made them popular as eco-friendly substitutes to ivory since they promote the development of forest communities without contributing to deforestation and animal poaching. In addition, they have been commercialized as microbeads to replace microplastics in cosmetic applications. However, this material is vulnerable to deterioration by micro-organisms and insects, as they are predominantly constituted by β-1,4-mannan, a hydrophilic polysaccharide similar to cellulose. In this context, seed endosperm was treated for 80 s by an atmospheric air plasma jet so as to modify its wettability, as plasma has been widely studied recently for seed disinfection and surface modification. Plasma treated samples were characterized by the water contact angle, AFM, and Raman imaging. Water contact angle results showed an increase from (31.5 ± 8.7)º to (78.9 ± 5.4)º, indicating incorporation of hydrophobic moieties to the sample surface. In turn, AFM images demonstrate the formation of a rough and heterogeneous coating that resembles epicuticular wax layers. Furthermore, principal component analysis of Raman imaging results evidenced contributions from wax (1156, 1170 and 1410 cm-1), carbohydrates (1020, 1080 and 1106 cm-1), and lignin (1573, 1635 and 1662 cm-1). These results indicate that plasma treatment promoted the migration of hydrophobic waxes to the surface and their crosslinking with fragmented cell wall material such as mannan, xylan, and lignin, promoting seed hydrophobization with no need for additional precursors or generation of side products.

scholarly journals Real-Time Monitoring of Biotinylated Molecules Detection Dynamics in Nanoporous Anodic Alumina for Bio-Sensing

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 478 ◽  
Author(s):  
Laura Pol ◽  
Chris Eckstein ◽  
Laura Acosta ◽  
Elisabet Xifré-Pérez ◽  
Josep Ferré-Borrull ◽  
...  
Keyword(s):  
Surface Modification ◽  
Real Time ◽  
Anodic Alumina ◽  
Label Free ◽  
Real Time Monitoring ◽  
Helpful Tool ◽  
Nanoporous Anodic Alumina ◽  
Efficient Detection ◽  
Sensitivity And Selectivity ◽  
Molecule Model

The chemical modification, or functionalization, of the surfaces of nanomaterials is a key step to achieve biosensors with the best sensitivity and selectivity. The surface modification of biosensors usually comprises several modification steps that have to be optimized. Real-time monitoring of all the reactions taking place during such modification steps can be a highly helpful tool for optimization. In this work, we propose nanoporous anodic alumina (NAA) functionalized with the streptavidin-biotin complex as a platform towards label-free biosensors. Using reflective interferometric spectroscopy (RIfS), the streptavidin-biotin complex formation, using biotinylated thrombin as a molecule model, was monitored in real-time. The study compared the performance of different NAA pore sizes in order to achieve the highest response. Furthermore, the optimal streptavidin concentration that enabled the efficient detection of the biotinylated thrombin attachment was estimated. Finally, the ability of the NAA-RIfS system to quantify the concentration of biotinylated thrombin was evaluated. This study provides an optimized characterization method to monitor the chemical reactions that take place during the biotinylated molecules attachment within the NAA pores.

scholarly journals Superhydrophilic Coating with Antibacterial and Oil-Repellent Properties via NaIO4-Triggered Polydopamine/Sulfobetaine Methacrylate Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2008
Author(s):  
Hsiu-Wen Chien ◽  
Hong-Yu Lin ◽  
Chau-Yi Tsai ◽  
Tai-Yu Chen ◽  
Wei-Nian Chen
Keyword(s):  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Deposition Process ◽  
Water Contact ◽  
Water Separation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Oil Water Separation ◽  
One Step ◽  
Oil Repellent

Superhydrophilic coatings have been widely used for the surface modification of membranes or biomedical devices owing to their excellent antifouling properties. However, simplifying the modification processes of such materials remains challenging. In this study, we developed a simple and rapid one-step co-deposition process using an oxidant trigger to fabricate superhydrophilic surfaces based on dopamine chemistry with sulfobetaine methacrylate (SBMA). We studied the effect of different oxidants and SBMA concentrations on surface modification in detail using UV–VIS spectrophotometry, dynamic light scattering, atomic force microscopy, X-ray photoelectron spectroscopy, and surface plasmon resonance. We found that NaIO4 could trigger the rate of polymerization and the optimum ratio of dopamine to SBMA is 1:25 by weight. This makes the surface superhydrophilic (water contact angle < 10°) and antifouling. The superhydrophilic coating, when introduced to polyester membranes, showed great potential for oil/water separation. Our study provides a complete description of the simple and fast preparation of superhydrophilic coatings for surface modification based on mussel-inspired chemistry.

Preparation and Characterization of Carrot Nanofiber and their Reinforced Nanocomposite Films

2020 ◽  
Vol 845 ◽  
pp. 15-20
Author(s):  
Yeng Fong Shih ◽  
Zhong Zhe Lai ◽  
Venkata Krishna Kotharangannagari
Keyword(s):  
Suspension Polymerization ◽  
Nanocomposite Films ◽  
Acid Neutralization ◽  
Water Contact ◽  
Radical Oxidation ◽  
Solution Casting Method ◽  
Surface Modified ◽  
Contact Angle Analysis ◽  
Tempo Radical

In this study, the cellulose nanofiber (CNF) was prepared using carrot slag discarded from industrial carrot juice. The FTIR results of the carrot fiber show that the impurities such as lignin have been removed after alkali and acid neutralization treatment. In addition, it was confirmed that the carrot nanofiber was successfully prepared by the 2,2,6,6-tetramethylpiperidine (TEMPO) radical oxidation method. Subsequently, the obtained nanofiber was surface modified by styrene suspension polymerization and silane coupling agent, respectively. The results of water contact angle analysis show that the hydrophobicity of the modified nanofibers was improved. Moreover, a set of nanocomposite films were prepared by incorporating carrot nanofiber into sodium alginate (SA) and polystyrene (PS), respectively by using solution casting method. The obtained results showed that the TEMPO radical oxidized nanofiber containing film had the best transmittance in SA nanocomposite series. On the other hand, styrene suspension polymerization modified nanofiber containing one exhibited the best transparency in PS nanocomposite series.

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