Immobilization of trypsin in the layer-by-layer coating of graphene oxide and chitosan on in-channel glass fiber for microfluidic proteolysis

The Analyst ◽  
2011 ◽  
Vol 136 (24) ◽  
pp. 5190 ◽  
Author(s):  
Huimin Bao ◽  
Qiwen Chen ◽  
Luyan Zhang ◽  
Gang Chen
Keyword(s):  
Graphene Oxide ◽  
Glass Fiber ◽  
Layer By Layer ◽  
Layer Coating

scholarly journals Microencapsulated Multi-functionalized Graphene Oxide Equipped With Chloroquine for Efficient and Sustained Sirna Delivery

2021 ◽  
Author(s):  
Rana Imani ◽  
Satya Prakash ◽  
Hojatollah Vali ◽  
John F. Presley ◽  
Shahab Faghihi
Keyword(s):  
Graphene Oxide ◽  
Cellular Uptake ◽  
Sirna Delivery ◽  
Layer By Layer ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Lysosomal Ph ◽  
Intracellular Targeting ◽  
Lysosomotropic Agent ◽  
Layer Coating

Abstract A multi-functionalized graphene oxide (GO)-based carrier with conjugation of aminated-polyethylenglycole (PEG-diamine), octaarginine (R8) and folic acid (FA), which also contains chloroquine (CQ), a lysosomotropic agent, is introduced. The cellular uptake mechanisms and intracellular targeting of FA functionalized nanocarriers are examined. The localized releases of CQ and siRNA intracellular delivery are evaluated. Microencapsulation of the nanocarrier complexed with genes in layer-by-layer coating of alginate micro-beads is also investigated. The covalently co-conjugated FA with PEG and R8 provides a stable formulation with increased cellular uptake compared to FA-free carrier. The CQ-equipped nanocarrier shows a 95% release of CQ at lysosomal pH. The localized release of the drug inside the lysosomes is verified which accelerates the cargo discharge into cytoplasm.

scholarly journals NANOCOATING OF POLYESTER FABRIC WITH GRAPHENE OXIDE

2019 ◽  
Vol 2019 ◽  
pp. 78-81
Author(s):  
Beyza DOĞAN ◽  
Şule Sultan UĞUR ◽  
Banu TÜRKASLAN
Keyword(s):  
Graphene Oxide ◽  
Multilayer Coating ◽  
Reduction Process ◽  
Polyester Fabric ◽  
Layer By Layer ◽  
Measuring Device ◽  
Hummers Method ◽  
Coating Method ◽  
Fabric Surface ◽  
Layer Coating

GO is easily dispersed in solvents, dielectric property, transparency, electronic features can be adjusted due to the superior mechanical properties and areas of use are expanding day by day. In this study, graphene oxide was obtained from graphite by using modified Hummers method and then applied to polyester fabric surface according to multilayer coating method. Contrary to the traditional Hummers method in the literature, this study was carried out without the use of NaNO₃ in order to be environmentally friendly. Based on the Layer-by-Layer coating method, GO based nano films have been applied to the polyester fabric surface. After obtaining the GO based nanocomposite polyester fabrics, it was treated with Na₂S₂O₄ and NaBH₄ in order to obtain RGO structure and GO reduction was achieved. A thin coating layer was observed in SEM analysis of the reduced graphene oxide (RGO) and GO coated fabrics. In the EDS analysis, increase in the amount of C and the decrease in the amount of O were determined after the reduction process. The most striking feature of graphene oxide was applied to all fabrics with a 4-probe measuring device and the best result was observed in the polyester fabric which was coated with Na₂S₂O₄ in 10 layer 5 minutes with Layer-by-Layer coating method with 1.47 × 1̄0 ³ S/cm².

Fabrication of layer-by-layer graphene oxide thin film on copper substrate by electrophoretic deposition

2020 ◽  
Vol 59 (12) ◽  
pp. 125001
Author(s):  
Nan Ye ◽  
Satoka Ohnishi ◽  
Mitsuhiro Okada ◽  
Kazuto Hatakeyama ◽  
Kazuhiko Seki ◽  
...  
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Electrophoretic Deposition ◽  
Copper Substrate ◽  
Oxide Thin Film ◽  
Layer By Layer ◽  
Layer Graphene

scholarly journals Thermally Stimulated Desorption Optical Fiber-Based Interrogation System: An Analysis of Graphene Oxide Layers’ Stability

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 70
Author(s):  
Maria Raposo ◽  
Carlota Xavier ◽  
Catarina Monteiro ◽  
Susana Silva ◽  
Orlando Frazão ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Layer By Layer ◽  
Film Stability ◽  
A Value ◽  
Device Reliability ◽  
Sensor Devices ◽  
Lbl Films ◽  
The Stability

Thin graphene oxide (GO) film layers are being widely used as sensing layers in different types of electrical and optical sensor devices. GO layers are particularly popular because of their tuned interface reflectivity. The stability of GO layers is fundamental for sensor device reliability, particularly in complex aqueous environments such as wastewater. In this work, the stability of GO layers in layer-by-layer (LbL) films of polyethyleneimine (PEI) and GO was investigated. The results led to the following conclusions: PEI/GO films grow linearly with the number of bilayers as long as the adsorption time is kept constant; the adsorption kinetics of a GO layer follow the behavior of the adsorption of polyelectrolytes; and the interaction associated with the growth of these films is of the ionic type since the desorption activation energy has a value of 119 ± 17 kJ/mol. Therefore, it is possible to conclude that PEI/GO films are suitable for application in optical fiber sensor devices; most importantly, an optical fiber-based interrogation setup can easily be adapted to investigate in situ desorption via a thermally stimulated process. In addition, it is possible to draw inferences about film stability in solution in a fast, reliable way when compared with the traditional ones.

scholarly journals Engineering of TiO2 or ZnO—Graphene Oxide Nanoheterojunctions for Hybrid Solar Cells Devices

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 75
Author(s):  
Duarte Carreira ◽  
Paulo A. Ribeiro ◽  
Maria Raposo ◽  
Susana Sério
Keyword(s):  
Graphene Oxide ◽  
Solar Cells ◽  
Fossil Fuels ◽  
Electrical Characterization ◽  
Modern Society ◽  
Clean Energy ◽  
Zno Films ◽  
Layer By Layer ◽  
Glass Substrates ◽  
Rc Circuit

It is currently of huge importance to find alternatives to fossil fuels to produce clean energy and to ensure the energy demands of modern society. In the present work, two types of hybrid solar cell devices were developed and characterized. The photoactive layers of the hybrid heterojunctions comprise poly (allylamine chloride) (PAH) and graphene oxide (GO) and TiO2 or ZnO films, which were deposited using the layer-by-layer technique and DC-reactive magnetron sputtering, respectively, onto fluorine-doped tin oxide (FTO)-coated glass substrates. Scanning electron microscopy evidenced a homogeneous inorganic layer, the surface morphology of which was dependent on the number of organic bilayers. The electrical characterization pointed out that FTO/(PAH/GO)50/TiO2/Al, FTO/(PAH/GO)30/ZnO/Al, and FTO/(PAH/GO)50/ZnO/Al architectures were the only ones to exhibit a diode behavior, and the last one experienced a decrease in current in a low-humidity environment. The (PAH/GO)20 impedance spectroscopy study further revealed the typical impedance of a parallel RC circuit for a dry environment, whereas in a humid environment, it approached the impedance of a series of three parallel RC circuits, indicating that water and oxygen contribute to other conduction processes. Finally, the achieved devices should be encapsulated to work successfully as solar cells.

Layer by layer assembled functionalized graphene oxide-based polymer brushes for superlubricity on steel-steel tribocontact

Soft Matter ◽  
2021 ◽  
Author(s):  
Suprakash Samanta ◽  
Rashmi Ranjan Sahoo
Keyword(s):  
Graphene Oxide ◽  
Nucleophilic Addition ◽  
Polymer Brushes ◽  
Addition Reaction ◽  
Layer By Layer ◽  
Functionalized Graphene ◽  
Covalent Functionalization ◽  
Functionalized Graphene Oxide ◽  
Nucleophilic Addition Reaction ◽  
Branched Polyethylenimine

Present study demonstrates a simple and multistep approach for the preparation of covalent functionalization of chemically prepared graphene oxide (GO) by branched polyethylenimine (PEI) through nucleophilic addition reaction to prepare...

Layer-by-layer of graphene oxide-chitosan assembly on PVA membrane surface for the pervaporation separation of water-isopropanol mixtures

2021 ◽  
Vol 38 (2) ◽  
pp. 411-421
Author(s):  
Shivshankar Chaudhari ◽  
KieYong Cho ◽  
SoHyan Joo ◽  
ByeongYun An ◽  
SongEun Lee ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Membrane Surface ◽  
Layer By Layer ◽  
Pervaporation Separation
Sign in / Sign up

Export Citation Format

Share Document