scholarly journals A Review on Graphene’s Light Stabilizing Effects for Reduced Photodegradation of Polymers

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Samira Karimi ◽  
Emna Helal ◽  
Giovanna Gutierrez ◽  
Nima Moghimian ◽  
Milad Madinehei ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Free Radical ◽  
Lattice Structure ◽  
High Surface ◽  
Hexagonal Lattice ◽  
High Surface Area ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Hydroxyl Groups ◽  
Graphene Derivatives

Graphene, the newest member of the carbon’s family, has proven its efficiency in improving polymers’ resistance against photodegradation, even at low loadings equal to 1 wt% or lower. This protective role involves a multitude of complementary mechanisms associated with graphene’s unique geometry and chemistry. In this review, these mechanisms, taking place during both the initiation and propagation steps of photodegradation, are discussed concerning graphene and graphene derivatives, i.e., graphene oxide (GO) and reduced graphene oxide (rGO). In particular, graphene displays important UV absorption, free radical scavenging, and quenching capabilities thanks to the abundant π-bonds and sp2 carbon sites in its hexagonal lattice structure. The free radical scavenging effect is also partially linked with functional hydroxyl groups on the surface. However, the sp2 sites remain the predominant player, which makes graphene’s antioxidant effect potentially stronger than rGO and GO. Besides, UV screening and oxygen barriers are active protective mechanisms attributed to graphene’s high surface area and 2D geometry. Moreover, the way that graphene, as a nucleating agent, can improve the photostability of polymers, have been explored as well. These include the potential effect of graphene on increasing polymer’s glass transition temperature and crystallinity.

Functionalized Nano-graphene Oxide as Multi-modal Clinic for Effective Drug Delivery

2017 ◽  
Vol 10 (4) ◽  
pp. 3768-3771
Author(s):  
Soumitra Satapathi ◽  
Rutusmita Mishra ◽  
Manisha Chatterjee ◽  
Partha Roy ◽  
Somesh Mohapatra
Keyword(s):  
Drug Delivery ◽  
Graphene Oxide ◽  
Cancer Cell ◽  
High Surface ◽  
High Surface Area ◽  
Cancer Cell Line ◽  
Xrd Analysis ◽  
Graphene Derivatives ◽  
Nano Graphene

Nano-materials based drug delivery modalities to specific organs and tissues has become one of the critical endeavors in pharmaceutical research. Recently, two-dimensional graphene has elicited considerable research interest because of its potential application in drug delivery systems. Here we report, the drug delivery applications of PEGylated nano-graphene oxide (nGO-PEG), complexed with a multiphoton active and anti-cancerous diarylheptanoid drug curcumin. Specifically, graphene-derivatives were used as nanovectors for the delivery of the hydrophobic anticancer drug curcumin due to its high surface area and easy surface functionalization. nGO was synthesized by modified Hummer’s method and confirmed by XRD analysis. The formation of nGO, nGO-PEG and nGO-PEG-Curcumin complex were monitored through UV-vis, IR spectroscopy. MTT assay and AO/EB staining found that nGO-PEG-Curcumin complex afforded highly potent cancer cell killing in vitro with a human breast cancer cell line MCF7.

scholarly journals Graphene- and Graphene Oxide-Based Nanocomposite Platforms for Electrochemical Biosensing Applications

2019 ◽  
Vol 20 (12) ◽  
pp. 2975 ◽  
Author(s):  
Madasamy Thangamuthu ◽  
Kuan Yu Hsieh ◽  
Priyank V. Kumar ◽  
Guan-Yu Chen
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Cell Capture ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Electrochemical Biosensing ◽  
Graphene Derivatives ◽  
Enzymatic Biosensors

Graphene and its derivatives such as graphene oxide (GO) and reduced GO (rGO) offer excellent electrical, mechanical and electrochemical properties. Further, due to the presence of high surface area, and a rich oxygen and defect framework, they are able to form nanocomposites with metal/semiconductor nanoparticles, metal oxides, quantum dots and polymers. Such nanocomposites are becoming increasingly useful as electrochemical biosensing platforms. In this review, we present a brief introduction on the aforementioned graphene derivatives, and discuss their synthetic strategies and structure–property relationships important for biosensing. We then highlight different nanocomposite platforms that have been developed for electrochemical biosensing, introducing enzymatic biosensors, followed by non-enzymatic biosensors and immunosensors. Additionally, we briefly discuss their role in the emerging field of biomedical cell capture. Finally, a brief outlook on these topics is presented.

scholarly journals Total phenolic content, free radical scavenging capacity, and anti-cancer activity of silymarin

2020 ◽  
Vol 10 ◽  
Author(s):  
Uyory Choe ◽  
Monica Whent ◽  
Yinghua Luo ◽  
Liangli (Lucy) Yu
Keyword(s):  
Free Radical ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Total Phenolic ◽  
Milk Thistle ◽  
Hydroxyl Groups ◽  
Dietary Polyphenols ◽  
Anti Cancer

Milk thistle (Silybum marianum) seeds are a good source of dietary polyphenols. The bioactive component of milk thistle seeds, silymarin, contains flavonolignans including silybin A, silybin B, isosilybin A, isosilybin B, silychristin, isosilychristin, and silydiain along with the flavonol taxifolin. Silymarin is used traditionally as a natural herbal medicine with minimal side effects. Structurally, each silymarin component possesses phenolic hydroxyl groups and thus works as an antioxidant. In addition to free radical scavenging capacities, silymarin’s anti-cancer activities were reported for many different types of cancers including bladder, breast, colon, gastric, kidney, lung, oral, ovarian, prostate, and skin. The current review will discuss silymarin’s chemical components, total phenolic content, free radical scavenging capacities, and anti-cancer activities.

scholarly journals Detection of Microorganisms Using Graphene-Based Nanobiosensors

2021 ◽  
Vol 59 (4) ◽  
Author(s):  
Mehrab Pourmadadi ◽  
Fatemeh Yazdian ◽  
Sara Hojjati ◽  
Kianoush Khosravi-Darani
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Behavior ◽  
High Surface ◽  
Graphene Quantum Dots ◽  
High Surface Area ◽  
Bacterial Cells ◽  
Design Strategies ◽  
Reduced Graphene ◽  
Graphene Derivatives ◽  
High Elasticity

Having an insight into graphene and graphene derivatives such as graphene oxide, reduced graphene oxide, and graphene quantum dots structures is necessary since it can help scientists to suspect the possible properties and features that using these carbon materials in preparation of a nanocomposite could bring out. In recent years, graphene and its derivatives are attractive with extensive applications in biosensors due to fascinating properties, such as high surface area, optical and magnetic properties, and high elasticity for the detection of microorganisms can be modified with some other materials such as macromolecules, oxide metals, and metals to improve the electrochemical behavior of the biosensor, and also can be modified with some other materials such as macromolecules, oxide metals, and metals to improve the electrochemical behavior of the biosensor. In this review paper, biosensors design strategies based on graphene and its derivatives (graphene-based nanocomposites in biosensors) are introduced. Then their application for the detection of microorganisms including Prions, Viroids, viral and bacterial cells as well as fungi, protozoa, microbial toxins, and even microbial-derived antibiotics are reviewed.

Free radical scavenging activity of ethanolic extracts from some Apiacean species

Planta Medica ◽  
2006 ◽  
Vol 72 (11) ◽  
Author(s):  
B Nickavar ◽  
FS Abolhasani ◽  
M Kamalinejad ◽  
MR Reza Khani ◽  
F Mojab
Keyword(s):  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Free Radical Scavenging Activity ◽  
Scavenging Activity ◽  
Ethanolic Extracts
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