Nanographene Oxide Research Articles

2023 TERMIS – AMERICAS Conference & Exhibition Boston Marriott Copley Place April 11–14, 2023

2023 TERMIS – AMERICAS Conference & Exhibition Boston Marriott Copley Place April 11–14, 2023

Fabrication of immobilized molybdenum complex on functionalized graphene oxide as a novel catalyst for the synthesis of benzothiazoles

This paper presented a novel amino-modified nano-graphene oxide supported thiophene-2-carbaldehyde Mo-complex (Mo(TC)/GO) catalyst prepared and characterized by FT-IR, SEM, TEM, TGA, EDX, BET, XRD, and N2 adsorption–desorption techniques. The catalyst presented an outstanding performance for synthesizing benzothiazole derivatives through a reaction between benzyl alcohol derivatives and 2-aminothiophenol. The heterogeneous catalyst could be facial separated and reused by filtration without any substantial decline in its catalytic activity even after five runs.

Toxic Effects of Nanographene Oxide on Testes of Rats

The current study aimed to examine the effects of nanographene oxide on the testes. A total of 48 male albino rats were randomly divided into 6 groups. The first, second, third, fourth, and sixth groups were treated with graphene oxide nanopowder at 20, 30, 40, 50, and 60 mg/kg concentrations, respectively. The sixth group was considered the control group. The results indicated a significant decrease in the average testis weight of rats treated with different nanographene oxide dosages, compared to the control group. There was also a significant decrease in the level of FSH and testosterone of treated rats with nanographene oxide, while there was no significant difference in the level of LH hormone when compared to the control group. The histological examination of the testes in the treated rats indicated hemorrhage, decreased sperm count, decreased thickness of the tubular epithelium, dissociation of connective tissue between the seminiferous tubules, in addition to hematological congestion, necrosis of the tubular epithelium, divergence of the seminal tubules, absence of sperm, shattering of the seminal tubule wall and degeneration sperm-forming cells and edema formation. Using the transmission electron microscope, the findings revealed a range of cellular changes, such as the presence of two-headed spermatids, the destruction of the nucleus membrane, spermatoblasts, the destruction of the cell membrane, and the denting of the nucleus membrane. It can be concluded that the nanographene oxide at 20-60 mg/kg concentrations can have harmful effects on spermatogenesis and normal function testis in rats.

Synthesis, Solvatochromism and Fluorescence Quenching Studies of Naphthalene Diimide Dye by Nano graphene oxide.

A naphthalene diimide dye with two side amine arm was prepared. Uv-Vis and fluorescence spectroscopic techniques are used for their photophysical and solvatochromic characteristics in different solvents. The Lippert-Mataga plot for naphthalene diimide demonstrated a negative linear dependence by increasing polarity. Results showed naphthalene diimide is more polar in the ground than in the excited state. A quenching study was conducted for interacting the naphthalene diimide as a fluorophore and graphene oxide as a quencher. Fluorescence quenching-based platforms in nanoscale have been used in sensing systems. Raman, FTIR, Uv-Vis and fluorescence spectroscopic techniques were used to study the quenching mechanism. The results indicated that graphene plays an effective quencher against the naphthalene diimide, with a quenching efficiency 91%. The Stern-Volmer analysis results show a mix of static and dynamic quenching mechanisms. The binding constant of the quencher-fluorophore and the number of binding sites have been reported. Thermodynamic parameters of their interaction were evaluated. The negative values of the Gibbs free energy confirm that the complexation process is spontaneous. Meanwhile, the positive entropy value confirms that the favorable pathway process.

Laboratory Investigation on the Rutting and Fracture Resistance of Hot-Mix Asphalt Containing Nanographene Oxide

The use of nanomaterials has brought about a huge revolution in the development of various industries. Moreover, in the pavement industry, researchers have been applying nanomaterials for many years due to their unique properties to enhance the features of asphalt mixtures and increase their resistance to various failures. In this study, nanographene oxide (GO) has been used in the amount of 0.2, 0.5, and 0.8 percent of consumed bitumen to improve the low-temperature cracking resistance and the high-temperature rutting resistance of hot-mix asphalt (HMA). For this purpose, to examine the impact of this material on the HMA, the semicircular bending (SCB) fracture test and Hamburg wheel tracking (HWT) test were applied. In addition, conventional bitumen tests were performed to investigate the impact of nanoGO on virgin bitumen in this study. The outcomes of conventional bitumen experiments displayed that the addition of nanoGO to pure bitumen augments viscosity, specific gravity, and softening point and reduces the penetration and ductility of pure bitumen. Furthermore, outcomes of the SCB fracture test indicated that nanoGO enhances the stress intensity factor (SIF) of the asphalt mixture and improves the low-temperature cracking resistance of asphalt specimens. Moreover, the addition of nanoGO to the asphalt mixture increased rutting resistance and decreased rutting depth. In addition, the results of the ANCOVA statistical analysis demonstrated the significant effect of this nanomaterial on the improvement of the low-temperature cracking resistance and the rutting resistance of HMA.

Investigation of Physochimechal and Biological Properties of Composite Sodium Alginate for Tissue Engineering

The current study involves synthesis of a composite films of sodium alginate (Alg), polyvinylalcohol and NanoGraphene oxide (GO) for tissue engineering applications. Solvent casting was used to make the polymeric composite films (Alg-Pva-Go), which may exhibit a synergic activity of the components for tissue repair. The influence of various GO concentrations on the films properties was also investigated. The scaffold has outstanding physicochemical and biological properties. The composite film's high swelling degree and contact angle reveals its high hydrophilicity, making it appropriate for tissue engineering. The antimicrobial activity on Staphylococcus aureus were studied. Furthermore, the antimicrobial test showed that the films composite was resistant to S. aureus. Seeding (AD-MSC) cells into the composite films exhibited an increase in cell adhesion and proliferation when compared to the Alginate and Polyvinylalcohol film in vitro experiments, indicating that the GO has a good influence on the films characteristics, which can utilization in tissue engineering applications.

Bioengineered liver crosslinked with nano-graphene oxide enables efficient liver regeneration via MMP suppression and immunomodulation

Decellularized extracellular matrix scaffold, widely utilized for organ engineering, often undergoes matrix decomposition after transplantation and produces byproducts that cause inflammation, leading to clinical failure. Here we propose a strategy using nano-graphene oxide to modify the biophysical properties of decellularized liver scaffolds. Notably, we demonstrate that scaffolds crosslinked with nano-graphene oxide show high resistance to enzymatic degradation via direct inhibition of matrix metalloproteinase activity and increased mechanical rigidity. We find that M2-like macrophage polarization is promoted within the crosslinked scaffolds, which reduces graft-elicited inflammation. Moreover, we show that low activities of matrix metalloproteinases, attributed to both nano-graphene oxide and tissue inhibitors of metalloproteinases expressed by M2c, can protect the crosslinked scaffolds against in vivo degradation. Lastly, we demonstrate that bioengineered livers fabricated with the crosslinked scaffolds remain functional, thereby effectively regenerating damaged livers after transplantation into liver failure mouse models. Overall, nano-graphene oxide crosslinking prolongs allograft survival and ultimately improves therapeutic effects of bioengineered livers, which offer an alternative for donor organs.

Surface Treatment by Physical Irradiation for Antifouling, Chlorine-Resistant RO Membranes

Reverse osmosis (RO) membranes represent a strategic tool for the development of desalination and water treatment processes. Today's global needs for clean water supplies show stressing circumstances to secure this supply, relying upon desalination and wastewater treatment and reuse, especially in Egypt and the Middle East. However, chlorine attack and fouling of polyamide layers, the active (selective) layers of RO membranes, are representing a great obstacle to seriously spreading the use of this technology. One promising way of fouling control and chlorine resistance is surface modification using grafting by plasma or vacuum ultraviolet (VUV) irradiation as a layer-by-layer assembly on polyamide membranes. Several studies have shown the effect of grafting by plasma using methacrylic acid (atmospheric pressure plasma) and showed that grafted coatings can improve PA membranes toward permeation compared with commercial ones with fouling behavior but not chlorine resistance. In this work, the techniques of layer-by-layer (LBL) assembly for previously prepared PA RO membranes (3T) using a mixed-base polymer of polysulfone and polyacrylonitrile in the presence of nanographene oxide (GO) without chemical grafting and with chemically grafted poly-methacrylic acid (3TG) were used. Membranes 3T, 3TG, a blank one (a base polymer membrane only was surface modified using VUV activation (AKT), and one with a grafted layer with polyethylene glycol (VUV-PEG) were prepared. These were then compared with polydimethylsiloxane (VUV-PDMS) and another surface modification with low-pressure plasma using acrylic acid (acryl) and hexadimethyl siloxane (GrowPLAS). The tested membranes were evaluated by short-term permeation and salt rejection experiments together with fouling behavior and chlorine resistance. A clear improvement of chlorine resistance and antifouling was observed for 3T membranes under plasma treatment, especially with the grafting with polyacrylic acid. Better antifouling and antichlorine behaviors were achieved with the vacuum UV treatment.

Preventive effects of nano-graphene oxide against Parkinson’s disease via reactive oxygen species scavenging and anti-inflammation

We investigated the neuroprotective effects of deca nano-graphene oxide (daNGO) against reactive oxygen species (ROS) and inflammation in the human neuroblastoma cell line SH-SY5Y and in the 6-hydroxydopamine (6-OHDA) induced Parkinsonian rat model. An MTT assay was performed to measure cell viability in vitro in the presence of 6-OHDA and/or daNGO. The intracellular ROS level was quantified using 2',7'-dichlorofluorescein diacetate. daNGO showed neuroprotective effects against 6-OHDA-induced toxicity and also displayed ROS scavenging properties. We then tested the protective effects of daNGO against 6-OHDA induced toxicity in a rat model. Stepping tests showed that the akinesia symptoms were improved in the daNGO group compared to the control group. Moreover, in an apomorphine-induced rotation test, the number of net contralateral rotations was decreased in the daNGO group compared to the control group. By immunofluorescent staining, the animals in the daNGO group had more tyrosine hydroxylase-positive cells than the controls. By anti-Iba1 staining, 6-OHDA induced microglial activation showed a significantly decrease in the daNGO group, indicating that the neuroprotective effects of graphene resulted from anti-inflammation. In conclusion, nanographene oxide has neuroprotective effects against the neurotoxin induced by 6-OHDA on dopaminergic neurons. [BMB Reports 2023; 56(3): 202-207].

Research on the Targeted Treatment of Squamous Cell Carcinoma by Nanographene Drug Delivery System

In order to find an effective cure for squamous cell carcinoma, we innovatively used nano-graphene oxide as a pharmaceutical delivery system, overcoming resistance to cisplatin-targeted anti-squamous carcinoma. For this purpose, we prepared a nano-graphene oxide using an oxidation method, functionally modified with polyethylene glycol (PEG) and branched polyethyleneimine (BPEI) and loaded with the antitumor drug cisplatin (CDDP), a compound with preliminary anticancer efficacy. Then, anti-human squamous cell carcinoma monoclonal antibody was combined to construct a target graphene nanopharmaceutical system. The administration system was applied to nude mice carrying human squamous cell carcinoma. Through the detection of frozen tissue slices, the anti-squamous cell carcinoma effect and targeting of the graphene nanoloaded system were analyzed. The safety of the pharmaceutical system was confirmed through further experiments. Results showed that the NGO-PEG-BPEI-CDDP-Antibody complex had a significant antitumor effect and was able to enter the nude mice and targeted squamous cell carcinoma cell and effectively kill squamous cell carcinoma cells, thus reducing the use of clinical chemotherapeutic drugs, improving the efficacy and providing a new answer for the treatment of squamous cell carcinoma.

Celastrol Loaded PEGylated Nanographene Oxide for Highly Efficient Synergistic Chemo/Photothermal Therapy.

The main aim of this study is to improve the solubility, reduce side effects and increase the therapeutic efficacy of CSL by using functionalized graphene oxide as a carrier, to fulfill chemo-photothermal therapy. Celastrol (CSL), which is extracted from the traditional Chinese medicinal plant Tripterygium wilfordii, has reported significant antitumor activity in vitro and in vivo cancer models. However, disadvantages with regard to solubility, short plasma half-life and toxicity hinder its use in pharmaceutical application. Nanocarrier delivery system could be employed to improve the biochemical and pharmacokinetic performance of CSL. Among numerous nanocarriers, graphene oxide is one of the most promising nanocarriers due to its intrinsic physical and chemical properties and good biocompatibility. Here, we employed a PEGylated reduced nanographene oxide CSL complex (nrGO-PEG/CSL) as a new drug delivery system to achieve highly efficient synergistic chemo/photothermal therapy. A functionalized nrGO-PEG was synthesized and the loading capacity of CSL, photothermal effect and release efficiency under different pH and NIR irradiation were measured in the first stage of work. In vitro and in vivo anticancer effects of prepared nrGO-PEG/CSL complex were evaluated on 4T1 cells and 4T1 tumor-bearing mice, respectively, with the association of NIR laser irradiation. The functionalized nrGO-PEG exhibited excellent drug loading capacity of CSL (20.76 mg/mg GO) and photothermal effect (~3.0 -fold increment over unreduced nGO-PEG). Loaded CSL could be efficiently released from nrGO-PEG/CSL complex by NIR irradiation in vitro. In vivo study performed on 4T1 tumor-bearing mice proved that nrGO-PEG/CSL with NIR laser irradiation shows superior anticancer effects. The experimental data demonstrated that the nrGO-PEG/CSL-mediated chemo/photothermal combination therapy was more cytotoxic to cancer cells than only chemotherapy or photothermal treatment, reducing the occurrence of tumor metastasis. Therefore, nrGO-PEG/CSL-mediated chemo/photothermal is expected to be a promising treatment for synergistic cancer therapy.

Mathematical Modeling Investigation of V+5 Ion Removal from Wastewater by Nanographene Oxide

The objective of this work is to remove Vanadium V+5 ions from wastewater by batch adsorption utilizing Nano Graphene Oxide (NGO) since Vanadium presents a hazardous concern due to its effect on biological systems; According to the International Agency for Research on Cancer (IARC), vanadium V+5 ions are a potential human carcinogen. In the adsorption process, the effects of temperature (20-50)°C and initial concentration effect (100-800) mg L-1 were investigated. The adsorption isotherms were identified using a simulated aqueous solution of the V+5 ions and a kinetic and thermodynamic sorption analysis. Both the Langmuir and Freundlich isotherm models were used to fit the data. Due to the correlation coefficient (R2) of 0.999, analyses showed that the Adsorption of V+5 ions by NGO followed the Langmuir model. Kinetic models analyzed Intra Particle Diffusion, Pseudo First & Second Order Models revealed that an Intra-Particle Diffusion model was followed. Thermodynamically, The Adsorption processes were exothermic, random, and spontaneous, all shown by the negative values for Enthalpy ∆H, Entropy ∆S, and Gibbs free Energy ∆G.

Physico-Antibacterial Feature and SEM Morphology of Bio-Hydraulic Lime Mortars Incorporating Nano-Graphene Oxide and Binary Combination of Nano-Graphene Oxide with Nano Silver, Fly Ash, Zinc, and Titanium Powders

The study evaluated the impact of graphene powders used as additives in the recipe of the experimental lime mortar to a mixture ratio of 1:2.5 of NHL3.5 hydraulic lime:fine sand. The content of binder, aggregate and water was kept constant, varying only the amount and the type of the added additives in relation to the amount of natural hydraulic lime NHL3.5. The following five types of experimental mortars were prepared as follows: reference mortar (without additive); mortars containing 1 wt.% GO and 5 wt.% GO powder; mortar with the following GO powders mixture: GO powder functionalized with silver nanoparticles and with fly ash (GO-Ag + GO-fly ash); mortar with the following GO powders mixture: GO with zinc oxide and with titanium oxide (GO-ZnO + GO-TiO2). The influence of the GO-based additive addition on the porosity, surface microstructure, and water sorption coefficient of the mortar samples was evaluated. The antibacterial effect of the mortar samples against three bacterial strains was also investigated. The best results were obtained for the experimental mortar containing GO-ZnO -TiO2, which showed improved experimental properties that potentially allow its use for the rehabilitation of heritage buildings.

Effects of adding functionalized graphene oxide nanosheets on physical, mechanical, and anti-biofilm properties of acrylic resin: In vitro- experimental study

Background: Polymethyl methacrylate resin is widely used in orthodontic treatments. Graphene oxide (GO) has reactive functional groups on its surface that facilitate binding to various materials such as polymers, biomolecules, DNA, and proteins. This study aimed to investigate the impact of adding functionalized GO nanosheets on the physical, mechanical, cytotoxicity, and anti-biofilm properties of acrylic resin.Materials and Methods: In this experimental study, fifty samples (for each test) were divided into groups of 10, in the form of acrylic resin discs with concentrations of 0, 0.25, 0.5, 1, and 2 weight percentage (wt%) of functionalized GO nanosheets and also the control group. Samples were evaluated in terms of physical properties (surface hardness, surface roughness, compressive strength, fracture toughness, and flexural strength), anti-biofilm properties (On four groups of micro-organisms, including Streptococcus mutans, Streptococcus sanguis, Staphylococcus aureus, and Candida albicans), and cytotoxicity. Data were analyzed using SPSS software version 22, descriptive statistics, one-way analysis of variance test, and Tukey post hoc test. The significance level was considered P < 0.05.Results: No significant difference was observed between the different groups with weight percentages of 0.25, 0.5, 1, and 2% nano GO (nGO) and the control group (without nGO) in terms of surface roughness and toughness. However, compressive strength, three-point flexural strength, and surface hardness showed significant differences between the groups. Furthermore, the degree of cytotoxicity increased by increasing the weight percentage of nano-GO.Conclusion: The addition of functionalized nGO in appropriate concentrations to polymethyl methacrylate can improve the anti-bacterial and anti-fungal biofilm properties without changing or increasing their physical and mechanical properties.

Modelling the quenching effect of chloroaluminum phthalocyanine and graphene oxide interactions: implications for phototherapeutic applications

Studying energy transfer between chloroaluminum phthalocyanine and nanographene oxide for combined phototherapies, this work reveals the role of molecular aggregation on fluorescence quenching using DFT and KMC simulations.

Graphene oxide supported ionic liquid/Fe complex: a robust and highly stable nanocatalyst.

Herein, a lamellar structured nano-graphene oxide supported ionic liquid/Fe complex (NGO/IL-Fe) is prepared through grafting of alkyl imidazolium chloride on the NGO followed by treatment with iron(iii) chloride hexahydrate. The NGO/IL-Fe nanomaterial was characterized by using FT-IR, PXRD, TGA, EDX and SEM techniques. NGO/IL-Fe was used as a robust and efficient nanocatalyst for the synthesis of tetrahydrobenzo[b]pyrans in water at 25 °C. The desired products were obtained in high yield over a relatively short time. The recoverability, reusability and also leaching tests were performed to study the stability and the nature of the designed catalyst under applied conditions.

Employing a Carbon-Based Nanocomposite as a Diffusive Solid-Phase Extraction Adsorbent for Methamphetamine for Therapeutic Purposes

Due to the obvious minimal doses of drugs in biological matrices as well as the societal difficulties caused by methamphetamine usage, methamphetamine identification is critical in clinical and forensic laboratories. Because of their simple and inexpensive production procedure, as well as their excellent selectivity and sensitivity, polymeric carbon-based nanocomposites are strong contenders for the diffusive solid-phase extraction approach. The diffusive solid-phase extraction absorbent nanographene oxide polypyrrole composite was produced and used to recover methamphetamine from a complicated urine substrate. The generated NGPPC was fully characterized, and the significant extracting parameters have been explored using the one-parameter-at-a-time strategy. NGOPC is being used to extract methamphetamine using a urine medium with high efficiency. The NGPPC synthesizing procedure was easy, and the extraction method will demonstrate good repeatability. Moreover, the practical and efficient synthesis process stimulates the use of carbon-based compounds in various extraction procedures. As for detecting and quantifying equipment, HPLC monitors are being used. 300 mL methanol, 7 min extracting and desorption duration, 5000 mixing frequency, urinary pH value of 20, 40 mg adsorption, and 5 mL amount of urine were the optimal extraction variables. Following tracing the calibration graph, the method’s linear ranges were determined to be 40-600 ng/ml. The detection limits (LOD) and quantitation limits (LOQ), correspondingly, were 10 and 35.80 ng/mL. The proposed methodology seemed to have a detection range of 9 ng/mL. The suggested approach’s applicability in numerous characterization and medical facilities was proven by the examination of addicted subjects using the proposed technique. For successful extraction of methamphetamine using biological urine samples, the carbon-based adsorbent was being used as diffusive solid-phase extraction adsorption.

Nano Graphene Oxide Embedded Hydroxyapatite Coating on AZ91D Mg Alloy at Various Voltage for Bone Implant Application​

Magnesium (Mg) and its alloys have been widely explored for biomedical applications as future biodegradable implant materials. Furthermore, a facile plasma electrolytic oxidation (PEO) technique was used to create biodegradable hydroxyapatite (HA) and nanographene oxide (nGO) coating on AZ91D Mg alloy. However, Mg and its alloy are vulnerable to the physiological environment, resulting in an untimely loss of mechanical power. Other than that, the coating factor for clinical application, such as HA, has barriers in hardness, strength, and wear resistance. This paper focuses on the physical properties and surface morphology of HA/nGO coating on AZ91D Mg alloy through PEO coating to solve the problem. The AZ91D Mg alloy was coated with HA/nGO using the PEO method at constant HA/nGO concentration and coating time, with variable voltages (115V, 230V, 345V, and 460V). Surface morphology analysis, elemental composition analysis and surface roughness, and were evaluated. Finally, the effect of a particular voltage level on the surface roughness at the constant coating time of 10 minutes indicates the surface roughness values of 1.6667 μm at 345V were obtained and demonstrate that HA/nGO samples are well disseminated at 345V coating compared to the other voltages.

Mathematical Modeling and Kinetics of Removing Metal Ions from Industrial Wastewater

The study's objective is to produce Nano Graphene Oxide (GO) before using it for batch adsorption to remove heavy metals (Cadmium Cd+2, Nickel Ni+2, and Vanadium V+5) ions from industrial wastewater. The temperature effect (20-50) °C and initial concentration effect (100-800) mg L-1 on the adsorption process were studied. A simulation aqueous solution of the ions was used to identify the adsorption isotherms, and after the experimental data was collected, the sorption process was studied kinetically and thermodynamically. The Langmuir, Freundlich, and Temkin isotherm models were used to fit the data. The results showed that Cd, Ni, and V ions on the GO adsorbing surface matched the Langmuir model with correlation coefficients (R2) of 0.999. Kinetic models studied showed that a pseudo-second-order model was followed and thermodynamically, the process was exothermic due to ∆H negative, the reduction in randomness because of negative ∆S. additionally, spontaneous adsorption of metal ions was ∆G negative values influenced.

Oxidation of Alcohols into Carbonyl Compounds Using a CuO@GO Nano Catalyst in Oxygen Atmospheres

In this article, the oxidation of alcohols into carbonyl compounds was studied in oxygen atmospheres using a copper oxide on graphene oxide (CuO@GO) nano composites catalyst, synthesized by the wet chemistry method. CuO@GO nano composites were prepared from GO, and CuO NPs by the sol-gel method. The transformation of aromatic alcohols into corresponding carbonyl compounds in good-to-high yields were observed using the CuO@GO catalyst under an oxygen atmosphere. Synthesized CuO@GO was confirmed by FT-IR, XRD, XPS, TEM, FE-SEM, TEM, and SEM analyses, and revealed intercalation of CuO-NPs on/in GO nano sheets through the chelation of Cu+2 ions with CO, COOH, and OH groups presenting on the GO nano sheets. The catalytic activity of CuO@GO nano composites for the conversion of alcohols into carbonyl compounds were evaluated through TOF (2.56 × 10−3 mol g−1 min−1). The use of CuO@GO has shown catalytic activity and recyclability with a high conversion of alcohols to ketones. We assume that the proposed CuO@GO catalyst can be used for other key organic transformations and will be evaluated in the future.