Potential Of Graphene Oxide Research Articles

Assessing the Antimicrobial Efficacy of Graphene Oxide and Its PEGylated Derivative Against Staphylococcus aureus

The rise of antimicrobial resistance (AMR) has become a critical health challenge. This, plus the antimicrobial discovery void, had led scientists to search for an effective alternative to antimicrobials. In this context, nanomaterials, such as graphene oxide (GO), a two-dimensional (2D) carbon molecule with oxidized functional groups, have been shown to interact physically and chemically with bacteria. Moreover, the addition of polyethylene glycol (PEG) to its surface enhances GO’s biocompatibility and water solubility, making it a promising candidate for biomedical applications. This study evaluates the antimicrobial efficacy of GO and its polyethylene glycol-modified form (GO-PEG) against Staphylococcus aureus, a bacterium responsible for numerous hospital-acquired and multidrug-resistant infections. After their production, both nanomaterials were characterized using various techniques to provide insight into their morphology, stability, and functional group composition. Then, the antimicrobial activity of GO and GO-PEG was assessed using the Müeller–Hinton broth microdilution method, determining the minimum inhibitory concentration (MIC) for S. aureus among ten different concentrations of both nanomaterials (from 0.0625 to 32 mg/mL). The results demonstrate the potential of GO as an effective antimicrobial agent at 16 and 32 mg/mL, offering new strategies in the fight against AMR. Further research could establish its role in future therapeutic applications.

Graphene oxide dispersed rose-petals based green chemistry synthesis of hybrid composite for novel spectroscopic applications

Rosa Santana family includes the rose, a highly prized decorative plant having symbolic, cultural, and commercial value. The exploration of graphene-based nanocomposites has expanded significantly, with recent research focusing on integrating these materials into natural and sustainable matrices. This study investigates the dispersion of graphene oxide (GO) within the biological structure of rose-petals, representing a novel approach to developing eco-friendly nanocomposites. The rich colours of the roses are ascribed to pigments such as flavanols, carotenoids, and anthocyanin. Carotenoids, which are found in natural colours including yellow, orange, violet, as well as another ingredient found in rose petals. By leveraging the inherent properties of rose petals, such as their unique properties and surface morphology and biocompatibility, this work highlights the potential of GO to enhance the mechanical, electrical, and optical characteristics of the composite. Advanced characterization techniques, including scanning electron microscopy (SEM), and electrochemical analysis, are employed to understand the interaction between GO and the rose petal substrate. The techniques of FT-IR, EDS, XRD, SEM, energy band gap, and CV were used in characterize the synthesis of doped graphene using rose petals extract. The findings underscore the synergistic effects of this natural-synthetic hybrid system, opening pathways to innovative applications in flexible electronics, biosensors, and sustainable material design. The novelty of this research lies in its foundational exploration of integrating graphene oxide with organic substrates like rose petals, offering a new direction for the development of environmentally benign graphene nanocomposites. Green chemistry based novel nanocomposite may open up new avenues for production of graphene oxide homogenious dispersion with rose-petal extract.

Additive-Free Gelation of Graphene Oxide Dispersions via Mild Thermal Annealing: Implications for 3D Printing and Supercapacitor Applications.

Herein, a mild thermal annealing (MTA) process is presented for additive-free gelation of graphene oxide (GO) dispersions. This process transitions the GO from a nematic liquid crystal phase to a random network structure, significantly enhancing its rheological properties by order of magnitude. This transition is facilitated by the diffusion of functional groups on the GO surface, which induces hydrophobic attractions, leading to a stable network structure. Employing rheo-SAXS experiments, detailed insights are provided into the microstructural changes of GO gel under shear stress, establishing a direct correlation between its rheological behavior and microstructure. The distinctive properties of MTA-processed inks are illustrated, seamlessly integrating with 3D printing, to yield a highly porous lattice structure that demonstrates promising potential as a supercapacitor electrode. The MTA process, an additive-free approach to gelation, maintains the inherent dispersion properties of GO while offering scalability. Thus, this method brings significant economic and environmental advantages compared to conventional gelation techniques. The findings not only advance the fundamental understanding of 2D colloidal network gels but also increase the potential of GO for a wide range of applications, from gas and liquid absorbers to electrodes for energy storage and conversion, and biomedical fields.

Evaluation of the performance enhancement of asphalt concrete via graphene oxide incorporation: A multi-test approach

The need for improved asphalt pavements has led to the exploration of nanomaterials such as graphene oxide (GO). This study investigates the potential of GO to enhance the performance of asphalt concrete (AC) with a nominal maximum aggregate size of 12.5 mm (AC_12.5) pavements, a commonly used material in highway construction that has not been extensively studied with GO modification. The main objective is to evaluate the impact of varying GO content (1%, 1.5%, and 2%) on the key technical properties of AC_12.5, including rutting resistance, moisture stability, and tensile capacity. A series of performance tests, including Marshall stability, residual stability, splitting tensile strength, and dynamic modulus, were conducted on AC_12.5 samples with varying GO content. Furthermore, a mechanistic– empirical (M-E) approach was employed to compare the rutting resistance of GO-modified pavements with that of conventional pavements. Initial findings suggest that GO incorporation significantly enhanced the mechanical properties of AC_12.5 compared with the control mixture. Performance tests indicated improved rutting resistance, moisture stability, and tensile capacity. The M– E analysis demonstrated superior rutting resistance in the GO-modified pavement structures. The findings confirm the potential of GO as a promising nanomaterial for enhancing the performance of AC_12.5 pavements. The observed improvements in key mechanical properties and rutting resistance suggest its feasibility for developing more durable, sustainable, and cost-effective roads in the future.

Characterization and Properties of Binder and Nano-Filler in Geopolymer Paste with Graphene Oxide

Globally, current research has developed new cement-based materials to meet increased demands for performance, energy efficiency, and environmental protection. Geopolymer, cost-effective, and high-early strength concrete binder alternative, has grown in popularity. Geopolymer reduces emissions by 80% during production while maintaining strength levels comparable to Ordinary Portland Cement (OPC). In their natural state, geopolymer binders have a microstructure that is cross-linked and significantly more brittle than OPC. To improve the properties of geopolymer, several approaches were adopted. However, recent study suggests that incorporating nanomaterials such as graphene oxide (GO) to geopolymer has shown an improvement in physical and mechanical properties. Graphene oxide is an inorganic nanomaterial that improves the mechanical characteristics of various composite materials by showing substantial filling effects on composite materials that significantly improve composite material integrity. The investigation into the potential of GO to improve the efficacy of geopolymer composite materials in various engineering applications has garnered considerable attention in recent years. The simplified hummer’s method was employed to synthesise the GO. Various characterization techniques involving SEM, XRD, and FTIR were utilized to understand the crystalline structure and microstructure of GO nanoparticles. GO powder were used as 0.05%, 0.10%, 0.15%, 0.20%, and 0.25% by weight of binder that includes fly ash class F and steel slag with an optimum binder modification of 40% fly ash and 60% steel slag. The influence of GO on Bulk density, microstructure, and mechanical strength were determined. The compressive strength results indicated an improvement of compressive strength by 21.48% in geopolymer paste with 0.15% GO after 28 days of curing.

Role of Graphene Oxide and Reduced Graphene Oxide in Electric Double-Layer Capacitors: A Systematic Review

The evolution of electric double-layer capacitors (EDLCs) has significantly benefited from advancements in graphene-based materials, particularly graphene oxide (GO) and reduced graphene oxide (rGO). This systematic review consolidates and analyzes existing research on the roles of GO and rGO in enhancing the performance of EDLCs, focusing on synthesis methods, electrode fabrication, electrolytes, and performance metrics such as capacitance, energy density, and cycling stability. Following the PICOS and PRISMA frameworks, a comprehensive literature search was conducted across Scopus, Web of Science, PubMed, and IEEE Xplore, covering the period from 2010 to 2023. A total of 128 articles were initially identified, with 27 studies meeting the inclusion criteria after rigorous screening and full-text analysis. Key findings reveal that the incorporation of GO and rGO in EDLCs leads to significant improvements in specific capacitance, energy density, and cycling stability. Notable advancements include novel synthesis techniques and composite materials such as nitrogen-doped graphene, graphene/polyaniline hybrids, and various metal oxide–graphene composites, which exhibit superior electrochemical performance. However, challenges such as material scalability, environmental sustainability, and consistency in synthesis methods remain. This review stresses the great potential of GO and rGO in the development of high-performance EDLCs and highlights the need for continued research to address existing challenges and further optimize material properties and fabrication techniques.

Role of graphene oxide infusion in concrete to elevate strength and fire performance in construction concrete

The study is centered on optimizing graphene oxide (GO) concentration in M30 designer mix concrete, aiming to enhance its performance under elevated temperatures and fire conditions. The findings revealed a significant 40 % increase in compressive strength with the addition of 0.05 wt% GO to M30 grade concrete after 28 days of curing in water. GO played a crucial role in mitigating the impact of high temperatures under heating in furnace and fire exposure under flame, resulting in reduced crack formation and a delayed temperature rise during thermal loading. In heat resistance assessments, GO concrete exhibited a substantial delay in temperature rise compared to plain concrete under controlled furnace conditions, showcasing superior resistance to elevated temperatures. Thermogravimetric analysis and Differential TG analysis elucidated the superior retention of water and hydrated products in GO concrete, even after exposure to high temperatures. Fire exposure tests demonstrated that GO concrete exhibited a much lower surface temperature (less than 50 °C) opposite to the flame (flame temperature ∼ 700 °C) within a 15 cm width of concrete. Additionally, fewer and less severe cracks appeared in the GO concrete compared to plain concrete, showcasing its anti-spalling behavior. The altered matrix porosity of GO concrete, creating nano- and microscale channels, contributed to reduced vapor pressure and mitigated crack formation. This comprehensive study underscores the potential of GO as a versatile additive in concrete, offering enhancements in strength, heat resistance, and fire performance for sustainable and resilient infrastructure development.

Theoretical and Experimental Analysis of Hydroxyl and Epoxy Group Effects on Graphene Oxide Properties.

In this study, we analyzed the impact of hydroxyl and epoxy groups on the properties of graphene oxide (GO) for the adsorption of methylene blue (MB) dye from water, addressing the urgent need for effective water purification methods due to industrial pollution. Employing a dual approach, we integrated experimental techniques with theoretical modeling via density functional theory (DFT) to examine the atomic structure of GO and its adsorption capabilities. The methodology encompasses a series of experiments to evaluate the performance of GO in MB dye adsorption under different conditions, including differences in pH, dye concentration, reaction temperature, and contact time, providing a comprehensive view of its effectiveness. Theoretical DFT calculations provide insights into how hydroxyl and epoxy modifications alter the electronic properties of GO, improving adsorption efficiency. The results demonstrate a significant improvement in the dye adsorption capacity of GO, attributed to the interaction between the functional groups and MB molecules. This study not only confirms the potential of GO as a superior adsorbent for water treatment, but also contributes to the optimization of GO-based materials for environmental remediation, highlighting the synergy between experimental observations and theoretical predictions in advances in materials science to improve sustainability.

Efficient removal of U(VI) from aqueous solution using poly(amidoxime-hydroxamic acid) functionalized graphene oxide.

The efficient development of selective materials for uranium recovery from wastewater and seawater is crucial for the utilization of uranium resources and environmental protection. The potential of graphene oxide (GO) as an effective adsorbent for the removal of environmental contaminants has been extensively investigated. Further modification of the functional groups on the basal surface of GO can significantly enhance its adsorption performance. In this study, a novel poly(amidoxime-hydroxamic acid) functionalized graphene oxide (pAHA-GO) was synthesized via free radical polymerization followed by an oximation reaction, aiming to enhance its adsorption efficiency for U(VI). A variety of characterization techniques, including SEM, Raman spectroscopy, FT-IR, and XPS, were employed to demonstrate the successful decoration of amidoxime and hydroxamic acid functional groups onto GO. Meanwhile, the adsorption of U(VI) on pAHA-GO was studied as a function of contact time, adsorbent dosage, pH, ionic strength, initial U(VI) concentration, and interfering ions by batch-type experiments. The results indicated that the pAHA-GO exhibited excellent reuse capability, high stability, and anti-interference ability. Specially, the U(VI) adsorption reactions were consistent with pseudo-second-order and Langmuir isothermal adsorption models. The maximum U(VI) adsorption capacity was evaluated to be 178.7mg/g at pH 3.6, displaying a higher U(VI) removal efficiency compared with other GO-based adsorbents in similar conditions. Regeneration of pAHA-GO did not significantly influence the adsorption towards U(VI) for up to four sequential cycles. In addition, pAHA-GO demonstrated good adsorption capacity stability when it was immersed in HNO3 solution at different concentrations (0.1-1.0mol/L) for 72h. pAHA-GO was also found to have anti-interference ability for U(VI) adsorption in seawater with high salt content at near-neutral pH condition. In simulated seawater, the adsorption efficiency was above 94% for U(VI) across various initial concentrations. The comprehensive characterization results demonstrated the involvement of oxygen- and nitrogen-containing functional groups in pAHA-GO in the adsorption process of U(VI). Overall, these findings demonstrate the feasibility of the pAHA-GO composite used for the capture of U(VI) from aqueous solutions.

The effect of graphene oxide on thermal, electrical, and mechanical properties of carbon/epoxy composites: Towards multifunctional composite material

AbstractThe focus of this research work is to investigate the influence of graphene oxide (GO) on the mechanical, thermal, and electrical properties of carbon fiber‐reinforced polymer (CFRP) composites. The solvent mixing method with the new addition of a mixing stage is introduced for uniform distribution of graphene oxide in polymer. Different weight percentages of graphene oxide (1%, 1.5%, and 2%) were incorporated into the epoxy matrix, and the resulting composites were subjected to electrical conductivity, thermal conductivity, and interlaminar shear strength (ILSS) testing. The findings revealed a positive influence on material properties with the percentage of GO. Especially, the electrical conductivity and ILSS values reached up to 7.05 S/m and 11.03 MPa, respectively, when 1.5% GO by weight of the resin was added. The improvement in ILSS reported by 40% compared to the neat CFRP, and this increment was attributed to enhanced bonding between the epoxy matrix and carbon fabric. Maximum thermal conductivity of 1.04 W/m°K obtained at 1% GO filler, which is 15% higher than neat epoxy composite. Overall, these results illustrate the potential of GO as a promising filler to improve the electrical, thermal, and mechanical properties of CFRP composites. Proper optimization of graphene content in a polymer is needed to achieve the best multifunctional composite materials.Highlights The new solvent mixing method is introduced for uniform distribution of graphene oxide in polymer. Maximum thermal and electrical conductivity obtained at different percentages of graphene content in composite. Positive improvement is observed in mechanical, thermal, and electrical at a specific percentage of graphene in the composite. Proper optimization of nanofiller content in composite is needed to assess for maximum performance.

Graphene oxide a promising formaldehyde scavenger of phenolic resin‐bonded plywood: From elaboration to evaluation

AbstractA long‐standing manufactured and most frequently used resin is phenol‐formaldehyde resin, which has currently reached new horizons by incorporating nano reinforcements, even at lower loadings. Nanostructured materials, particularly graphene, have gained considerable interest in recent years because of their fascinating characteristics. Herein, this study explores for the first time the potential of prepared graphene oxide (GnO) as an effective formaldehyde scavenger in the development of plywood panels containing PF resins. The addition of 1% of GnO to the system resulted in a significant improvements in the mechanical properties by more than 45% in the shear strength (SS), 35% in modulus of elasticity, and 25% in modulus of rupture when compared with the reference panel. While the moisture resistance of panels were found to remarkably enhanced showing an increase in SS by 25% and 37% After 24 h in cold water (20°C) and 12 h of immersion in boiling water, respectively. The results also demonstrated that GnO exhibited exceptional formaldehyde capture efficiency, surpassing 60% reduction compared with the control. This innovative research not only unveils the novel potential of GnO in improving the performance of PF resins but also ushers in a new way of developing eco‐friendly wood‐based materials.

Application of Graphene Oxide in Oral Surgery: A Systematic Review.

The current review aims to provide an overview of the most recent research in the last 10 years on the potentials of graphene in the dental surgery field, focusing on the potential of graphene oxide (GO) applied to implant surfaces and prosthetic abutment surfaces, as well as to the membranes and scaffolds used in Guided Bone Regeneration (GBR) procedures. "Graphene oxide" and "dental surgery" and "dentistry" were the search terms utilized on the databases Scopus, Web of Science, and Pubmed, with the Boolean operator "AND" and "OR". Reviewers worked in pairs to select studies based on specific inclusion and exclusion criteria. They included animal studies, clinical studies, or case reports, and in vitro and in vivo studies. However, they excluded systematic reviews, narrative reviews, and meta-analyses. Results: Of these 293 studies, 19 publications were included in this review. The field of graphene-based engineered nanomaterials in dentistry is expanding. Aside from its superior mechanical properties, electrical conductivity, and thermal stability, graphene and its derivatives may be functionalized with a variety of bioactive compounds, allowing them to be introduced into and improved upon various scaffolds used in regenerative dentistry. This review presents state-of-the-art graphene-based dental surgery applications. Even if further studies and investigations are still needed, the GO coating could improve clinical results in the examined dental surgery fields. Better osseointegration, as well as increased antibacterial and cytocompatible qualities, can benefit GO-coated implant surgery. On bacterially contaminated implant abutment surfaces, the CO coating may provide the optimum prospects for soft tissue sealing to occur. GBR proves to be a safe and stable material, improving both bone regeneration when using GO-enhanced graft materials as well as biocompatibility and mechanical properties of GO-incorporated membranes.

Effect of graphene oxide on cement mortar under quasi-static and dynamic loading

Cement composites are the most widely used construction material in the world; however, research on their resistance to high strain loads is lacking. This study investigated the effect of graphene oxide (GO) on the static and dynamic mechanical properties and microstructure of cement mortar. Dynamic tests were performed using a split Hopkinson pressure bar apparatus at strain rates up to approximately 290 s−1. The mechanical behaviors of mortar specimens infused with 0.005 and 0.01 wt% GO (weight% of GO to cement) were compared against control specimens made with ordinary Portland cement. Enhancement in the strength of cement composites was evident in both compression and split-tension when GO was added in specific doses, particularly at higher strain rates. Correlation between the dynamic increase factor and the applied strain rate is found based on the compressive and split-tensile experimental data of tested mortar specimens. The findings of this study highlight the great potential of GO for improving the performance of cement composites under high strain rate loading.

Abstract LB334: Assessment of the potential of graphene oxide as an antigen delivery platform for cancer immunotherapy

Abstract Introduction: Novel cancer immunotherapies are urgently needed due to a lack of definitive treatments, as well as toxicity and cost of current therapies. 2-dimensional carbon graphene oxide (GO) nanomaterials provide a large surface area, high protein loading efficiency and good biocompatibility, as well as being inexpensive. Given these properties, we investigated whether and how GO could be an effective antigen delivery system for targeted cancer immunotherapies. Methods: GO was non-covalently complexed with the model antigen ovalbumin peptide (OVA257-264) and the immunostimulant and toll-like receptor 3 agonist polyinosinic:polycytidylic acid (Poly (I:C)). We examined innate and adaptive immune responses after subcutaneous injection of GO complexes by histology and flow cytometry. Results: We found that GO without Poly (I:C) had a very limited immunogenic potential. In contrast, GO complexed with Poly (I:C) significantly increased immune cell recruitment to the injection site, and enhanced activation and migration of dendritic cell subsets (cDC1s and cDC2s) in skin-draining lymph nodes 24 hours after injection. Additionally, we found that GO complexed with Poly (I:C) dramatically enhanced OVA-specific CD8+ T cell expansion and cytotoxic potential in both spleen and skin-draining lymph nodes 7 days after subcutaneous complex administration to mice which had previously been injected intravenously with traceable, OVA-specific (OT-I) CD8+ T cells. Conclusion: Our results have revealed the immunomodulatory potential of GO when complexed with Poly (I:C) by attracting immune cells to the injection site and augmenting antigen-specific cytotoxic responses both locally and systemically. Ongoing work is determining the anti-tumor potential of this approach, and potential mechanisms by which GO complexes might limit tumor progression. Citation Format: Sorayut Chattrakarn, Grace Mallett, Helen Parker, Neus Lozano, Kostas Kostarelos, Andrew S. MacDonald. Assessment of the potential of graphene oxide as an antigen delivery platform for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB334.

Thrust characteristics of nano-carbon/Al/oxygenated salt nanothermites for micro-energetic applications

Combustion within small motors is key in the application-specific development of nanothermite-based micro-energetic systems. This study evaluates the performance of nanothermite mixtures in a converging-diverging nozzle and an open tube. Mixtures were prepared using nano-aluminum (n-Al), potassium perchlorate (KClO4), and different carbon nanomaterials (CNMs) including graphene-oxide (GO), reduced GO, carbon nanotubes (CNTs) and nanofibers (CNFs). The mixtures were packed at different densities and ignited by laser beam. Performance was measured using thrust measurement, high-speed imaging, and computational fluid dynamics modeling, respectively. Thrust, specific impulse (ISP), volumetric impulse (ISV), as well as normalized energy were found to increase notably with CNM content. Two distinctive reaction regimes (fast and slow) were observed in combustion of low and high packing densities (20% and 55%TMD), respectively. Total impulse (IFT) and ISP were maximized in the 5% GO/Al/KClO4 mixture, producing 7.95 mN·s and 135.20 s respectively at 20%TMD, an improvement of 57% compared to a GO-free sample (5.05 mN·s and 85.88 s). CFD analysis of the motors over predicts the thrust generated but trends in nozzle layout and packing density agree with those observed experimentally; peak force was maximized by reducing packing density and using an open tube. The numerical force profiles fit better for the nozzle cases than the open tube scenarios due to the rapid nature of combustion. This study reveals the potential of GO in improving oxygenated salt-based nanothermites, and further demonstrates their applicability for micro-propulsion and micro-energetic applications.

Graphene oxide disruption of homeostasis and regeneration processes in freshwater planarian Dugesia japonica via intracellular redox deviation and apoptosis

The aquatic system is a major sink for engineered nanomaterials released into the environment. Here, we assessed the toxicity of graphene oxide (GO) using the freshwater planarian Dugesia japonica, an invertebrate model that has been widely used for studying the effects of toxins on tissue regeneration and neuronal development. GO not only impaired the growth of normal (homeostatic) worms, but also inhibited the regeneration processes of regenerating (amputated) worms, with LC10 values of 9.86 mg/L and 9.32 mg/L for the 48-h acute toxicity test, respectively. High concentration (200 mg/L) of GO killed all the worms after 3 (regenerating) or 4 (homeostasis) days of exposure. Whole-mount in situ hybridization (WISH) and immunofluorescence analyses suggest GO impaired stem cell proliferation and differentiation, and subsequently caused cell apoptosis and oxidative DNA damage during planarian regeneration. Mechanistic analysis suggests that GO disturbed the antioxidative system (enzymatic and non-enzymatic) and energy metabolism in the planarian at both molecular and genetic levels, thus causing reactive oxygen species (ROS) over accumulation and oxidative damage, including oxidative DNA damage, loss of mitochondrial membrane integrity, lack of energy supply for cell differentiation and proliferation leading to retardance of neuron regeneration. The intrinsic oxidative potential of GO contributes to the GO-induced toxicity in planarians. These data suggest that GO in aquatic systems can cause oxidative stress and neurotoxicity in planarians. Overall, regenerated tissues are more sensitive to GO toxicity than homeostatic ones, suggesting that careful handling and appropriate decisions are needed in the application of GO to achieve healing and tissue regeneration.

Effect of graphene oxide on the uptake, translocation and toxicity of metal mixture to Lepidium sativum L. plants: Mitigation of metal phytotoxicity due to nanosorption

Due to its unique structure and exceptional properties, graphene oxide (GO) is increasingly used in various fields of industry and therefore is inevitably released into the environment, where it interacts with different contaminants. However, the information relating to the ability of GO to affect the toxicity of contaminants is still limited. Therefore, the aim of our study was to synthesize GO, to examine the phytotoxicity of different concentrations of GO and its co-exposure with the metal mixture using garden cress (Lepidium sativum L.) as a test organism and to evaluate the potential of GO to affect toxicity of metals and their uptake by plants. The metal mixture (MIX) containing Ni (II), Zn (II), Cr (III) and Cu (II) was prepared in accordance with the maximum-permissible-concentrations (MPC) accepted for the inland waters in the EU. Additionally, the capacity of GO to adsorb metals was studied in specific conditions of the phytotoxicity test and assessed using adsorption isotherms. Our data indicate that in most cases the tested concentrations of MIX, GO and MIX + GO did not affect seed germination, root growth and biomass of roots and seedlings, however, they were found to alter photosynthesis processes, enhance production of carotenoids and H2O2 as well as to activate lipid peroxidation. Additionally, our study revealed that GO affects the accumulation of tested metals in roots and shoots of the MIX-exposed L. sativum. This is due to the capacity of GO to adsorb metals from the growth medium. Therefore, low concentrations of GO can be used for water decontamination.

Carboxymethyl Chitosan-Modified Graphene Oxide as a Multifunctional Vector for Deltamethrin Delivery and pH-Responsive Controlled Release, Enhanced Leaf Affinity, and Improved Mosquito-Killing Activity.

Traditional deltamethrin (DM) formulations (e.g., emulsifiable concentrates, wettable powders, etc.) have significant disadvantages of poor water dispersion stability, burst release, weak leaf affinity, short duration, poor efficacy, and high environmental toxicity. A nanomaterial-based pesticide delivery system (PDS) has provided effective strategies for green preparation and synergism of pesticide formulations. In this article, we developed carboxymethyl chitosan (CMCS)-modified graphene oxide (GO) as a vector for DM and constructed a pH-responsive PDS for Culex pipiens pallens control. GO-CMCS possesses excellent pesticide loading performance for DM (loading rate 87.76%). After being loading on GO-CMCS, the GO-CMCS-DM has a significantly improved dispersion stability in water. The GO-CMCS-DM exhibits pH-responsive controlled release performance, which can sustain the release of DM into the medium, maintaining an effective long-term concentration. Additionally, the leaf adhesion of GO-CMCS-DM is better than that for free DM, which can improve the pesticide utilization. Therefore, GO-CMCS-DM has a prolonged persistent period and sustained activity against Culex pipiens pallens. Considering the industrialization potential of GO, we believe that GO will play an important role in the pest control and antiepidemic fields.

The Potential of Graphene Oxide and Reduced Graphene Oxide in Diagnosis and Treatment of Cancer.

Nanotechnology is a pioneer field of study for engineering smart nanosystems in targeted diagnosis and treatment in cancer therapy. Effective treatment for various types of solid tumors should ideally target malignant cells and tissue while having no effect on healthy cells in the body. Nano-sized graphene oxide (GO) and reduced graphene oxide (rGO) have phenomenal chemical versatility, high surface area ratio, and supernatural physical properties. The synergistic effects caused by the well-defined assembly of GO and rGO surface generate not only essential optical, mechanical, but also electronic behaviors. In multimodal cancer therapy, developing innovative multifunctional hybrid nanoparticles with significant potential is extensively considered. GO and rGO are programmable targeted delivery systems infused with photonic energy that may be used in photothermal treatment. Its remarkable properties indicated its applications as a biosensor, bio-imaging for cancer diagnosis. In this current review, we show a remarkable highlight about GO, rGO, and discuss the notable applications for cancer diagnosis and treatment, and provide an overview of possible cellular signaling pathways that are affected by GO, rGO in cancer treatment.

Synthesis of graphene oxide coated metal powders with improved flowability and reduced reflectance

In this study, a method has been developed to coat metal powder particles (Fe, 316L stainless steel and Cu) with graphene oxide (GO). The method is based on using a pH window where opposite zeta potentials cause the GO sheets to be attracted to the passive oxide layer of the metal powder surface and a rotary evaporator mixing to achieve good dispersion and control the concentration of GO. The pH-dependent interactions of GO and Cu and Fe metal powders in solution have been investigated by mixing the metal powder with GO dispersions between pH 4.2 and 11.3, and it could be observed that GO attached to the metal powder surfaces up to pH ~8 for both Cu and Fe. At lower pH the zeta potential of GO becomes less negative and oxidation of the metal becomes more prominent. Based on these observations, a pH window just below the IEP of the surface metal oxides was used to adhere GO on metal powders in a rotary evaporator with controlled GO concentrations and good distribution of the GO sheets which was verified with SEM and Raman spectroscopy mapping. X-ray diffraction and Raman spectroscopy has been used to evaluate the GO and the metal oxides. Some relevant powder properties were investigated before and after coating of GO. The reflectance of Cu powders in the near-infrared 1070 nm wavelength range was reduced by up to 66 %, depending on the amount of GO coating. Flowability measurements showed that the flowability of the coated 316L powder could be improved significantly while the flowability of pure Fe powder was relatively unaffected by the coating. The results show that GO coated metal powder can be useful in additive manufacturing processes using a laser powder fusion technique where low reflectance and high flowability are important.