This article investigated the kinetic studies of thorium adsorption from an aqueous solution with graphene oxide functionalized with aminomethyl phosphonic acid (AMPA) as an adsorbent. First, the AMPA-GO adsorbent was characterized using TEM, XRD, and FTIR methods. Experiments were performed in two batch and continuous modes. In batch mode, adsorption kinetics were studied in different pH (1-4), temperature (298-328 K), initial concentration (50-500 mg L-1), and dosages (0.1-2 g L-1). The results showed that thorium adsorption kinetic follows pseudo-first-order kinetic model and that the adsorption reaction is endothermic. The maximum experimental adsorption capacity of thorium ions was observed 138.84 mg g-1 at a pH of 3, adsorbent dosage of 0.5 g L-1, and a temperature of 328 K. The results showed that AMPA-GO adsorbent can be used seven times with an acceptable change in adsorption capacity. In continuous conditions, the effect of feed flow rate (2-8 mL min-1), initial concentration (50-500 mg L-1), and column bed height (2-8 cm) was investigated. The continuous data was analyzed using the Thomas, Yoon-Nelson, and Bohart-Adams models. The experimental data of the column were well matched with the Thomas, and Yoon-Nelson models. The research results showed that the use of functionalized graphene oxide adsorbents has a great ability to remove thorium from aqueous solutions.

Graphene oxide (GO) nanoparticles are attracting growing interest in various fields, not least because of their distinct characteristics and possible uses. However, concerns about their impact on neurological health are emerging, underlining the need for in-depth studies to assess their neurotoxicity. This study examines GO exposure\'s neurobehavioral and biochemical effects on the central nervous system (CNS). To this end, we administered two doses of GO (2 and 5 mg/kg GO) to mice over a 46-day treatment period. We performed a battery of behavioral tests on the mice, including the open field to assess locomotor activity, the maze plus to measure anxiety, the pole test to assess balance and the rotarod to measure motor coordination. In parallel, we analyzed malondialdehyde (MDA) levels and catalase activity in the brains of mice exposed to GO nanoparticles. In addition, X-ray energy dispersive (EDX) analysis was performed to determine the molecular composition of the brain. Our observations reveal brain alterations in mice exposed to GO by intraperitoneal injection, demonstrating a dose-dependent relationship. We identified behavioral alterations in mice exposed to GO, such as increased anxiety, decreased motor coordination, reduced locomotor activity and balance disorders. These changes were dose-dependent, suggesting a correlation between the amount of GO administered and the extent of behavioral alterations. At the same time, a dose-dependent increase in malondialdehyde and catalase activity was observed, reinforcing the correlation between exposure intensity and associated biochemical responses.

Graphene-based materials are actively being investigated as sensing elements for the detection of different analytes. Both graphene grown by chemical vapor deposition (CVD) and graphene oxide (GO) produced by the modified Hummers\' method are actively used in the development of biosensors. The production costs of CVD graphene- and GO-based sensors are similar; however, the question remains regarding the most efficient graphene-based material for the construction of point-of-care diagnostic devices. To this end, in this work, we compare CVD graphene aptasensors with the aptasensors based on reduced GO (rGO) for their capabilities in the detection of NT-proBNP, which serves as the gold standard biomarker for heart failure. Both types of aptasensors were developed using commercial gold interdigitated electrodes (IDEs) with either CVD graphene or GO formed on top as a channel of liquid-gated field-effect transistor (FET), yielding GFET and rGO-FET sensors, respectively. The functional properties of the two types of aptasensors were compared. Both demonstrate good dynamic range from 10 fg/mL to 100 pg/mL. The limit of detection for NT-proBNP in artificial saliva was 100 fg/mL and 1 pg/mL for rGO-FET- and GFET-based aptasensors, respectively. While CVD GFET demonstrates less variations in parameters, higher sensitivity was demonstrated by the rGO-FET due to its higher roughness and larger bandgap. The demonstrated low cost and scalability of technology for both types of graphene-based aptasensors may be applicable for the development of different graphene-based biosensors for rapid, stable, on-site, and highly sensitive detection of diverse biochemical markers.

UNASSIGNED: This in vivo study evaluated the effect of graphene oxide and graphite coatings, coupled with the micro-arc oxidation (MAO) surface roughening technique, known for their mechanical strength, chemical stability, and antibacterial properties. The main objective was to assess the degree of improvement in osseointegration of titanium implants resulting from these interventions.
UNASSIGNED: In this study, 32 female rats were utilized and randomly allocated into four groups (n = 8 each): machined surface titanium implants (control), those roughened by the MAO method, those coated with graphene oxide-doped MAO, and those with a graphite-doped MAO coating. Titanium implants were surgically placed in the right tibia of the rats. Rats undergoing no additional procedures during the 4-week experimental period were sacrificed at the end. Then, the implants and surrounding bone tissues were separated and embedded in acrylic blocks for reverse torque analysis. Using a digital torque device, the rotational force was applied to all samples using a hex driver and racquet until implant separation from the bone occurred, with the corresponding values recorded on the digital display. Then, statistical analysis was performed to analyze the data.
UNASSIGNED: No statistically significant difference between the groups was observed in the biomechanical bone-implant connection levels (N/cm) (P = 0.268). Post-hoc tests were not required because no discernible differences were identified between the groups.
UNASSIGNED: Within the scope of this study, implants treated with the MAO method, along with those coated with graphene oxide- and graphite-doped MAO method, did not exhibit significant superiority in terms of osseointegration compared to machined surface titanium implants.

This study investigates the rheological, morphological, and mechanical properties of melt-processed polylactide/ethylene vinyl alcohol (70PLA/30EVOH) blend composites containing 0.25, 0.5, and 1 wt.% of graphene oxide (GO) nanoplates. Thermodynamic-based suggested the localization of nanoparticles in EVOH, SEM studies showed that the introduction of GO to the blend increased dispersed droplet size, which was attributed to the localization of GO within EVOH, as confirmed by TEM. The rheology results indicated a decrease in the elasticity for the composite containing 0.25 wt.% of GO compared to the neat blend, which was attributed to the sliding effect of the added GO nanoplatelets. However, samples containing higher amounts of GO nanoplatelets exhibited more excellent elasticity than the neat blend. The increased elasticity was suggestively attributed to the dominance of hydrodynamic interactions, the physical network of added nanoplatelets, and polymer/GO interactions over the sliding role of the GO nanoplatelets at higher loadings. In addition, the effect of the order of mixing was investigated, and the premixing of PLA and GO exhibited a decrease in the droplet radius compared to the neat blend. It was ascribed to the localization of GO nanosheets in the PLA and interface, which was confirmed by rheological results and mechanical assessments.

This study focuses on synthesizing and characterizing a graphene oxide/ZnTiO3/TiO2 (GO/ZTO/TO) composite to efficiently remove methylene blue (MB) from water, presenting a novel solution to address industrial dye pollution. GO and ZTO/TO were synthesized by the modified Hummers and sol-gel methods, respectively, while GO/ZTO/TO was prepared using a hydrothermal process. The structural and surface properties of the composite were characterized using various analytical techniques confirming the integration of the constituent materials and suitability for dye adsorption. The study revealed that GO/ZTO/TO exhibits an adsorption capacity of 78 mg g-1 for MB, with only a 15% reduction in adsorption efficiency until the fifth reuse cycle. Furthermore, the study suggests optimal adsorption near neutral pH and enhanced performance at elevated temperatures, indicating an endothermic reaction. The adsorption behavior fits the Langmuir isotherm, implying monolayer adsorption on homogeneous surfaces, and follows pseudo-second-order kinetics, highlighting chemical interactions at the surface as the rate-limiting step. The photocatalytic degradation of MB by GO/ZTO/TO follows pseudo-first-order kinetics, with a higher rate constant than that of GO alone, demonstrating the enhanced photocatalytic activity of the composite. In conclusion, GO/ZTO/TO emerges as a promising and sustainable approach for water purification, through an adsorption process and subsequent photocatalytic degradation.

Wound healing is a complex biological process crucial for restoring tissue integrity and preventing infections. The development of advanced materials that facilitate and expedite the wound-healing process has been a focal point in biomedical research. In this study, we aimed to enhance the wound-healing potential of hydrogel scaffolds by incorporating graphene oxide and poly (ethylene glycol) methyl ether methacrylate (MEO2MA). Various masses of graphene oxide were added to MEO2MA hydrogels via free radical polymerisation. Comprehensive characterizations, encompassing mechanical properties, and biocompatibility assays, were conducted to evaluate the hydrogels\' suitability for wound healing. In vitro experiments demonstrated that the graphene oxide-based hydrogels exhibited a proper swelling degree and tensile strength, responding effectively to moisture conditions and adhesiveness for wound healing. Notably, the tensile strength significantly increased to 626 kPa in the graphene oxide hydrogels. Biocompatibility assessments revealed that the graphene oxide/MEO2MA hydrogels were non-toxic to human dermal fibroblast cell growth, with no significant difference in cell viability observed in the graphene oxide/MEO2MA hydrogel (H-HG) group. In a rat skin experiment, the wound-healing rate of the hydrogel incorporating graphene oxide surpassed that of the pristine hydrogel after a 15-day treatment, achieving over 95% wound closure in the H-HG group. The histopathological analysis further supported the efficacy of the H-HG hydrogel dressing in promoting more effective tissue regeneration. These results collectively highlight the potential of the graphene oxide/MEO2MA hydrogel scaffold as a promising dressing for medical applications.

The most recent structural study of graphene oxide (GO) indicates that the oxidized debris (ODs) adhered to as-prepared GO will strip in certain aquatic settings. The impact of ODs stripping on the characteristics of GO has been widely reported, but its effects on GO aggregation have received less attention. Here, the influence of OD stripping on the GO aggregation property was identified, and the aggregation of as-prepared GO and GO upon OD stripping was compared. Upon ODs stripping, the pKa values of GO shifted from 3.91, 6.25, and 9.84 to 4.54, 6.65, and 10.21, respectively. Further analysis indicated the removal of ODs reduced the net negative charge and improved the hydrophobicity of GO, hence promoting the aggregation of GO. The acceleration of GO-Ca2+-OD aggregate formation was facilitated by the collective effects of ODs stripping, functional group deprotonation, double layer compression, OD bridging, and charge neutralization. The metal ions and stripped ODs attach to GO edges and link GO, which perform like bridges and contribute to further aggregation. In general, the existence of ODs adds complexity to the constructions and characteristics of GO, and it is important to take this into account while evaluating the aggregation characteristic of GO-based materials.

Introduction Graphene oxide (GO) has emerged as a promising material in dentistry, leveraging its exceptional properties. This study evaluates the physicochemical attributes of GO and elucidates its derived biological properties. These encompass biocompatibility, antibacterial efficacy, as well as its influence on osteogenic and odontogenic differentiation processes. Understanding the intricate interplay between the physicochemical and biological aspects of GO provides valuable insights into its potential applications in various dental contexts. Materials and methods The study group (so; titanium discs surface coated with GO) and the control group (co; plain/uncoated machined titanium discs) were divided based on cell attachment and cell proliferation assays (n=60). These groups were further divided into subgroups (n=30) based on the tested time intervals, specifically 24 hours, 48 hours, and 72 hours. The study and controlgroups were further subdivided into three subgroups (n=10) based on the microorganisms tested i.e Porphyromonas gingivalis, Prevotella intermedia and Fusobacteria nucleatum. Results The results of this in vitro study suggest that GO-coated titanium dental implants have both increased osteogenic potential and antimicrobial efficacy. Graphene has good potential as a promising alternative to traditional surface treatments, and a graphene-coated implant can be used for enhanced osseointegration.  Conclusion The osteogenic potential and the cell attachment were higher on titanium surfaces coated with GO nanoparticles when compared to plain titanium discs at 24, 48 and 72 hours respectively.

The present study serves experimental and theoretical analyses in developing a hybrid advanced structure as a photolysis, which is based on electrospun Graphene Oxide-titanium dioxide (GO-TiO2) nanofibers as an electron transfer material (ETMs) functionalized for perovskite solar cell (PVSCs) with GO. The prepared ETMs were utilized for the synthesis of mixed-cation (FAPbI3)0.8(MAPbBr3)0.2. The effect of GO on TiO2 and their chemical structure, electronic and morphological characteristic were investigated and discussed. The elaborated device, namely ITO/Bl-TiO2/3 wt% GO-TiO2/(FAPbI3)0.8(MAPbBr3)0.2/spiro-MeTAD/Pt, displayed 20.14% disposition and conversion solar energy with fill factor (FF) of 1.176%, short circuit current density (Jsc) of 20.56 mA/cm2 and open circuit voltage (VOC) 0.912 V. The obtained efficiency is higher than titanium oxide (18.42%) and other prepared GO-TiO2 composite nanofibers based ETMs. The developed materials and device would facilitate elaboration of advanced functional materials and devices for energy storage applications.