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Conjugated Graphene Gold Nanocomposites for Cancer Therapy
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Zaira Zaman Chowdhury, Abu Nasser Faisal, Shahjalal Mohammad Shibly, Devarajan Thangadurai, Saher Islam, Jeyabalan Sangeetha
Sonication and photo-aided deposition, like MWT, promote fast heating of the mixture, but the mechanism is markedly dissimilar for both circumstances. Ultrasonic reduction, as well as the photo-irradiated reduction, are both environmentally friendly, one-pot fabrication approach for the synthesis of rGO–AuNPs composites (Bai and Shen 2012). However, the autoclave atmosphere dictates whether the procedure is hydrothermal or solvothermal. Au nano-crystals, having size ranges from 10 to 20 nm, were decorated over GO without the application of any reductants or capping agents using hydrothermal approach (Qin et al. 2012). Electrochemical deposition is facilitated by the application of a voltage differential. This straightforward, environmentally friendly, cost-effective, and quick technique aims to produce dense, homogenous nanocomposites using only the precursors (Pham et al. 2011; Bai and Shen 2012).
Regeneration: Nanomaterials for Tissue Regeneration
Published in Harry F. Tibbals, Medical Nanotechnology and Nanomedicine, 2017
Another class of important biomaterials for regenerative medicine is the bioreactive ceramics and glasses. In addition to bioactive glasses and glass-ceramics, these include dense hydroxylapatite ceramics and similar materials. These can be formed on the surfaces of strong metal implants to improve their biocompatibility, tissue adhesion, and durability using techniques like electrochemical deposition. They are especially useful in bone restoration and bone and joint implants to bond the implant more naturally to the adjoining tissue and significantly prolong its lifetime. Nanotechnology is guiding the design of nanocomposites with enhanced mechanical properties to reduce fatigue failures due to crack initiation and propagation in implants that undergo physiological loading [3,4].
Presentation Format
Published in Kitsakorn Locharoenrat, Research Methodologies for Beginners, 2017
Synthesis of nanowires: The synthesis of nanowires could be carried out in two methods. The first one is the electroless plating. In this method, we deposit the amyloid fibrils over the top of carbon-coated nickel grid support, and then reducing agents (i.e., sodium borohydride) and stabilizers (i.e., CTAB or sodium citrate) are added. Hence, copper or silver nanoparticles are synthesized over the top of these deposited amyloid fibrils. Another method is to allow the conjugation of the nanoparticles on the top of the amyloid fibrils by allowing it to remain in an eppendorf tube for overnight at room temperature and then centrifuging and removing unreacted nanoparticles. By this method, we are able to synthesize nanowires ranging from 400 nm to several micrometers of different configurations and these nanowires could be characterized by using TEM. The same biotemplated nanowires could be characterized by using UV, IR, and Raman spectroscopy technique. By using Raman, we could also probe the interaction of individual nanoparticles over the surface of the amyloid fibrils. These information are very valuable to study the interaction between inorganic and biomolecules in forming the nanowires.Synthesis of nanoclusters: The nanoclusters could be synthesized by depositing the individual nanoparticles (i.e., platinum, palladium, or silver nanoparticles) over the surface of the alumina or silica support. This could be performed by electrochemical deposition technique. The growth of the nanoclusters could be studied by using different techniques, such as transmission electron microscope, UV, IR, and Raman spectroscopy techniques. This is because each nanocluster would have a definite shape and a route of conjugation of the nanoparticles to form nanoclusters. Then, the orientation of the lattice planes could be understood to probe the structural morphology of these nanoclusters. Additionally, AFM could be used to study the topology of these synthesized nanoclusters and elemental analysis of these nanoclusters could be performed by using TEM techniques.
Recent trends and perspectives in enzyme based biosensor development for the screening of triglycerides: a comprehensive review
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Vinita Hooda, Anjum Gahlaut, Ashish Gothwal, Vikas Hooda
In a TG biosensor based on impedimetric technique, there is electrochemical deposition of polyaniline nanotubes (PANI-NT) onto the surface of indium-tin-oxide (ITO) coated glass plate. Then, covalent immobilization of enzyme- lipase is done by using glutaraldehyde. The change in the charge transfer resistance (RCT) of PANI-NT film as a result of production of fatty acid molecules during TG hydrolysis, detects the varying concentration of TG. The fabricated Lipase/PANI-NT/ITO bioelectrode for the detection of TG in sera displayed sensitivity of 2.59 × 10−3 K Ω−1 mg/dL and linearity ranging from 25 mg/dL to 300 mg/dL with a short response time of 20 s [35]. These biosensors are easy to incorporate into microprocessor-controlled diagnostic tools and hence used as powerful method to estimate TG concentration. The demerits include the requirement of technological precision of the device along with the operating procedures [36].
Stimuli-responsive graphene-incorporated multifunctional chitosan for drug delivery applications: a review
Published in Expert Opinion on Drug Delivery, 2019
Sahar Gooneh-Farahani, M. Reza Naimi-Jamal, Seyed Morteza Naghib
Water contamination containing various pollutants such as heavy metal ions and toxic dyes is one of the most important global problems that have harmful effects on human health and environment. Various methods have been developed for purification of contaminated water such as adsorption, reverse osmosis, ion exchange, filtration through membrane, flocculation, and electrochemical deposition [281–286]. Among these, the absorption method is widely used due to an easy and convenient operation, low cost fabrication, and environmental compatibility. Different materials such as silica, gel, polymer materials, active alumina, metal oxides, activated carbons, carbon nanotubes and graphene are used for water purification as adsorbent [287–291]. Nanostructured adsorbents with a high surface area and active site provide a higher surface area than bulk materials. Graphene is an ideal substance as absorbent due to its excellent properties such as flexibility and mechanical strength, thermal and chemical stability, and especially the high surface area [292,293]. Graphene; however, is not suitable for a wide range of pollutants. Graphene shows a high absorption of organic compounds due to the presence of only sp2 carbon atoms on its surface, but is not a suitable adsorbent for metal ions and anionic dyes with a negative charge. The existence of oxygen-containing groups on the GO surface increases the adsorption of ions and positive charge compounds, but GO is still not suitable for adsorption of negative charge dyes. In addition, graphene tends to accumulate in a layer-to-layer form, therefore, there is a good absorbent design to solve the mentioned problems.
Biointerface: a nano-modulated way for biological transportation
Published in Journal of Drug Targeting, 2020
Pravin Shende, Varun S. Wakade
For example, peptide nucleic acid-DNA (PNA-DNA) is hybridised between PNA-functionalised carbon nanotubes and DNA. The modification of the amino group by DNA sequence with 5′-end interacts covalently on the surface of carbon nanotubes and leads to the formation of an amide linkage. The DNA sequence with 3′-terminal showed adsorption at the walls of CNTs by hydrophobic attractions. DNA probes were immobilised on the tips and walls of CNTs to examine the hybridisation reactions of two altered arrangements corresponding to Au-Np-labelled paired structures. This study justifies the arranged CNT electrodes with a modified DNA molecule to signify a novel approach for sequence-specific DNA sensing. The assemblies for nano-biointerfaces include physical and chemical adsorptions, self-assembly, sol–gel phenomenon, electrochemical deposition and electrochemical polymerisation methods [20]. Generation of nanostructured biointerface functionalised with biomolecules are physically and chemically adsorbed on the porous carbon bases that resemble vitreous carbon, pyrolytic graphite and basal plane pyrolytic graphite. The cell surface is coated using alkaline aqueous or non-aqueous coating solution like sodium hydroxide followed by evaporation of droplet. For instance, the aqueous coating solution is useful for electroanalysis of haemoglobin to create carbon dots (CDs) by breaking the bond between the carbon atoms. The enzyme electrode is unclear, depending on the effective immobilisation of horse-radish peroxidase (HRP) to the Au–Np-chitosan-entrapping carbon electrode [33]. Furthermore, biosensor shows the right electrocatalyst action by reducing hydrogen peroxide. The solubilised form of CNTs in an aqueous solution of chitosan biopolymer is coated on the glassy surface of carbon electrodes for the development of biosensor. Sol–gel methods form solid materials by interacting with nanocarriers at the ambient condition to form nanostructure biointerface [34]. 3D networks are created by encapsulating the biomolecules because the sol-gel matrix retains their reactivity.