News — graphene oxide research

Packaging in the food industry is changing. As consumers become more aware of the detriments of single use plastics, there is pressure within the supply chain to eliminate these, whilst maintaining a high standard of quality.  It is essential that new packaging technologies do not compromise on protection; the current standards of freshness must be maintained by ensuring that packaging is waterproof and doesn’t break or promote deterioration of food. This is especially important during transport, which is often on a global scale and will inevitably result in some strain on the packaging. Many research departments are striving to not just match the level of protection provided by conventional packaging today, but to improve properties such as anti-microbial activity, UV blocking and breathability, in order to ensure that the new packaging is a desirable and cost effective alternative.

Gelatin based biopolymers are being considered as a possible alternative to plastic, as gelatin is widely accessible, inexpensive and easy to process. However, the biopolymer is also susceptible to bacterial attack, breaks easily and is highly sensitive to moisture which decreases its suitability as a packaging material. The incorporation of graphene oxide into the polymer matrix has been shown to improve all these properties, as well as promoting thermal and light stability. GO is particularly suited to this use as, like gelatin, it is biodegradable (albeit with emzymes) and hence, environmentally benign. Gelatin alone would degrade too easily, but GO addition strengthens the material sufficiently that it is much more likely to withstand transport and handling. Furthermore, since GO interacts and bonds strongly, other additives can easily be included in the polymer composite to further enhance the material.

A recent study shows that combining a gelatin polymer with GO nanosheets and mussel-inspired polydopamine (PDA) resulted in a vastly tougher material with significant advantages. Mussels have been found to be remarkably good at sticking to a wide variety of surfaces, including plenty that are adhesion resistant. This led to in-depth studies of the proteins they secrete and resulted in PDA use becoming increasingly common. Here, GO was considered an effective means of transporting PDA, and PGO was synthesised (PDA-GO).

GO acted as an excellent cross-linking agent and enabled the integration of silver and cellulose into the structure, which previously required toxic chemicals and complex processes. These additives further enhanced anti-microbial and strengthening properties respectively. The large number of components essentially filled gaps within the biopolymer matrix, hence it’s improved impermeability against UV light and water. This is somewhat surprising, as GO is often hailed as a permeable material and is being widely applied to water filtration systems. However, in this instance, the hydrogen bonding from the GO reduced the availability of hydrophilic groups in the composite and therefore decreased water uptake.

Compared to other processes towards forming gelatin biopolymers, GO nanosheets enabled a much simpler and more environmentally friendly route, which resulted in a biodegradable polymer that was effective against common bacteria including E. coli and S. aureus.

This application is just one of many that utilise the unique properties of graphene and graphene oxide and further demonstrates the wide range of potential applications. If you have any enquiries about the applications of graphene oxide or how it can improve your existing applications, please get in touch and one of the GOgraphene team will be happy to help.

Industrial Crops and Products, 2019, 132, pp.197-212.

Lung cancer is the most common cause of cancer death in both men and women. Annually, there are more deaths from lung cancer alone than from colon, prostate and breast cancer combined. Cisplatin is a chemotherapeutic drug used to treat lung cancer cells by destroying rapidly dividing cells by damaging nuclear DNA.

Research published in the American Chemical Society investigates the effect of co-administrating graphene oxide nanoplatelets with cisplatin for the treatment of human lung cancer A459 cells. The presence of oxygen containing functional groups on the surface of graphene oxide increase solubility, dispersibility and biocompatibility. These properties make graphene oxide suitable for use as drug carriers in drug delivery and in live cell imaging. The co-administration of graphene oxide with cisplatin showed a decrease in the percentage of viable cancer cells when compared to cisplatin alone. As the concentration of cisplatin was increased, the effect of graphene oxide co-administration on cell viability was greater. This research highlights the possibility of graphene oxide use extending into the pharmaceutical industry.

This application is just one of many studied by academic groups to utilise the unique properties of graphene oxide. If you have any enquiries about the applications of graphene oxide or how it can improve your existing applications, please get in touch and one of the GOgraphene team will be happy to help.

Langmuir, 2019, 35, 3176−3182

Hemocompatibility describes the interaction between a foreign substance and blood. It is considered one of the most important issues in tissue engineering. A collaboration between Assuit University, Stockholm University and Kangwon National University demonstrated that hemolysis assays on graphene oxide showed no hemolytic effect (destruction of red blood cells). Sonication of graphene oxide suspension increases the zeta potential which increases the dispersion stability. Cell attachment and rapid division of cells is supported by the ultrasonicated graphene oxide because of its cytocompatibility. It also promotes formation of new bone.

Research published in Materials Science and Engineering showed that ultrasonicated graphene oxide is biocompatible with human foetal osteoblast cells, human endothelial cells and mouse embryonic fibroblasts. The study showed that cell proliferation measured by optical density was most efficient in the epithelial wound using 1% ultrasonicated graphene oxide when compared to a control. The wound showed the most improvement when compared on day 1 to day 3.

Studying osteoblast growth and activity with ultrasonicated graphene oxide showed that it enhances the cell adhesion and proliferation. This is because graphene oxide acts as a scaffold for the regeneration of bone tissue.

This research serves as another great example of how graphene oxide has the potential to enable a diverse range of innovations and applications. The graphene oxide supplied through GOgraphene is being used in both academic and industrial research in many sectors. If you are interested in using graphene oxide in your research, please let us know and a member of the team will be happy to help you.

Materials Science & Engineering, C, 2019, 94, 484–492

RSC Adv., 2015,5, 10782-10789 

Recently, our GOgraphene powder was characterised by Fourier Transform Infra-Red Spectroscopy Attenuated Total Reflectance (FTIR-ATR). In these measurements, infrared light is passed into an ATR crystal to reflect against the sample with a short penetration depth to minimise noise in the spectrum as graphene oxide is a 2D material. The material is then scanned over several angles of incidence and the refracted beam is detected to give the spectra across 600-4000 cm^-1. The peaks shown in the spectrum indicate the characteristic bond vibrations between elements in the sample. For more information, please visit our analytical data page.

If there is any additional information on FTIR, or other analytical data that you feel would be beneficial for your research, please get in touch through our enquiry form and one of the GOgraphene team will be in touch.

Anti-corrosion coatings have become increasingly more important in the developing world, with industrial equipment requiring protection from corrosive mediums such moisture, industrial chemicals or abrasion. With the global market now valued at $24 billion and expected to reach $36 billion by 2024, new technologies are under research with greater anti-corrosion properties. Considering it’s the strongest material known to man, it’s no surprise that graphene falls within this umbrella of research.

One of the first papers that explored a scalable route to anti-corrosion graphene coatings was produced by researchers at the University of Manchester, who utilised graphene oxide as an inert barrier. The hexagonal array of carbon atoms in graphene oxide act as a very effective barrier in water purification applications, with the oxygen functionalities providing defects and pathways for only the diffusion of water and small ions such as chlorides. In this research, graphene oxide was chemically reduced to restore the pristine graphene lattice. This coating was now impermeable to small ions as well as water, allowing it to be an effective anti-corrosion barrier for moisture and sea salt. The chemical inertness of graphene also gave this coating very high chemical corrosion resistance, proven in this research by exposing the surface to nitric, hydrochloric and even hydrofluoric acids whilst showing zero degradation.

In the same year, the anti-bacterial properties of graphene oxide were demonstrated in a biomedical application as a nanopaint for protection against bacteria to reduce incidences of heathcare-associated infection. Graphene oxide was incorporated into the paint through a simple balling milling technique, which was then coated onto substrates before subjecting to incubation with E.coli, P. aeruginosa and S. aureus. After 48 hours, the graphene oxide paint reduced the populations of these bacteria by 94, 88 and 85%, respectively, demonstrating its effectiveness as an antibacterial coating. These are just two of the many studies understanding the versability of graphene in coating applications, and if you’d like to find out more about this research topic, please do get in touch.

Nature Communications, 2014, 5, 4843, 1-5

Carbon, 2014, 72, 328-337