Carbon nanostructures: a comprehensive review of potential applications and toxic effects

Volatile organic compounds (VOCs) detection for the identification of bacterial infections in clinical wound samples

Early detection of wound infections is critical for timely intervention and prevention of possible complications since prompt treatment can help lower pathogen spread and enhance faster healing. Early detection also helps reduce the risk of serious infections requiring extensive medical interventions or life-threatening diseases such as sepsis. Culture-based approaches currently used for bacterial identification have limited sensitivity and specificity. At the same time, they are time-consuming, resulting in delays in therapy and, therefore, having a negative impact on the treatment outcomes. Quantifying the volatile organic compounds (VOCs) released by bacteria residing in wounds is a promising, non-invasive option for detecting infections at early stages. This method allows for continuous monitoring without requiring invasive procedures, thereby reducing patient discomfort and the risk of further complications. Spectroscopy methods and sensors are the primary VOC detection and quantification approaches, but sensors are more rapid, cost-effective, non-invasive, and precise. This review highlights the significance of the early detection of wound infection to enable timely intervention and prevent complications, emphasizing the limitations of culture-based approaches. It also explores the potential of quantifying VOCs using different methods and discusses the correlation between their levels and the rate of bacterial infections in wounds. Additionally, the review evaluates current VOC-based monitoring methods for wound management, identifies gaps in the field, and advocates for further research to advance wound care and enhance patient outcomes.

Environmental Toxicity of Cement Nanocomposites Reinforced with Carbon Nanotubes

The addition of carbon nanotubes (CNTs) to cement matrix brings multiple beneficial effects ranging from improving mechanical and physical properties to the creation of smart materials. When subjected to an erosive environment or as end-of-life waste, mortars with CNT addition might get released into the environment and come in contact with surface waters. The assessment of the environmental impact of mortars reinforced with carbon nanotubes is an important factor concerning their sustainability, as it has not yet been addressed in the literature. The presented paper aims to assess the water toxicity of cement mortars with various dosages of 0.05 wt.%, 0.1 wt.%, and 0.2 wt.% of carbon nanotube. The effect of the quality of water dispersion of CNTs was also considered through two sonication times of the suspension: 20 min and 60 min. Tests using indicator organisms, Aliivibrio fischeri, Daphnia magna, and Lemna minor, were conducted on shredded and non-shredded mortars. The results reveal no to low toxicity for all tested mortars under the assumed framework of toxicity assessment. The toxicity results for samples containing CNTs were comparable to those without CNTs, indicating that the toxicity of mortars incorporating CNTs is not greater than that of conventional cement-based materials. The water toxicity of the cement mortars is rather connected with the washing away of the hydration products more than with the presence of carbon nanotubes.

Green Synthesis of Red Fluorescent Graphene Quantum Dots Using Withania somnifera Leaves: Exploring Antidiabetic and Antioxidant Potential

In recent years, green synthesis methods for producing nanomaterials have gained significant interest due to their environmentally friendly nature and wide-ranging applications. The present study addresses a novel green synthesis of graphene quantum dots (GQDs) using leaves of Withania somnifera. The size, morphology, and stability of the green-synthesized GQDs were characterized using TEM, UV-Visible spectroscopy, Fluorescence spectrophotometer, XRD, and DLS. The bio-functional properties of the GQDs were investigated, with a focus on their antidiabetic and antioxidant capabilities. Their antidiabetic activity was assessed by examining their ability to inhibit α-amylase and α-glucosidase enzymes, which play a crucial role in glucose metabolism. Additionally, their antioxidant properties were evaluated using DPPH● scavenging assays, highlighting their effectiveness in neutralizing free radicals. The findings revealed that the synthesized GQDs outperformed the original leaf extract in both antioxidant activity and enzyme inhibition. The study revealed that the leaf extract exhibited higher IC50 values for inhibiting DPPH (78.508 ± 5.71), α-amylase (161.909 ± 6.188), and α-glucosidase (133.345 ± 7.328) compared to synthesized GQDs, which showed lower IC50 values of 72.74 ± 5.9, 137.966 ± 6.95, and 122.084 ± 5.478, respectively. The findings indicate that Withania somnifera derived GQDs hold significant potential for medical applications, warranting further investigation into their therapeutic efficacy. This study offers a comprehensive analysis of the fundamental biological properties of GQDs, addressing the dual challenges of antidiabetic and antioxidant activity.

Carbon-Based 3D Architectures as Anodes for Lithium-Ion Battery Systems

Graphite, with its exceptional cyclic performance, continues to dominate as the preferred anode material for lithium-ion batteries. However as high-energy application gains momentum, there is growing demand for higher capacities that alloying/de alloying and conversion type anode materials can offer. Despite their potential, these materials are plagued by challenges such as volumetric fluctuations, low conductivities, and poor cyclic stability. Carbon nanostructures, on the other hand, show tremendous promise with their low volume expansion, high ion diffusion rates, and excellent conductivity. Nevertheless, their limited areal and volumetric densities restrict their widespread utilization. To address these limitations, various strategies such as doping, composite formation, and structural modification have been proposed. This article provides a succinct overview of carbon nanomaterials and their electrochemical performance as 3D carbon-based anodes, along with a comprehensive analysis of the strategies employed to overcome associated challenges while evaluating their potential prospects in the field.

Carbon Quantum Dots: Properties, Preparation, and Applications

Carbon quantum dots are a novel form of carbon material. They offer numerous benefits including particle size adjustability, light resistance, ease of functionalization, low toxicity, excellent biocompatibility, and high-water solubility, as well as their easy accessibility of raw materials. Carbon quantum dots have been widely used in various fields. The preparation methods employed are predominantly top-down methods such as arc discharge, laser ablation, electrochemical and chemical oxidation, as well as bottom-up methods such as templates, microwave, and hydrothermal techniques. This article provides an overview of the properties, preparation methods, raw materials for preparation, and the heteroatom doping of carbon quantum dots, and it summarizes the applications in related fields, such as optoelectronics, bioimaging, drug delivery, cancer therapy, sensors, and environmental remediation. Finally, currently encountered issues of carbon quantum dots are presented. The latest research progress in synthesis and application, as well as the challenges outlined in this review, can help and encourage future research on carbon quantum dots.

Thermo-Mechanical Performance of Epoxy Hybrid System Based on Carbon Nanotubes and Graphene Nanoparticles

This study focuses on epoxy hybrid systems prepared by incorporating multi-wall carbon nanotubes (MWCNTs) and graphene nanosheets (GNs) at two fixed filler amounts: below (0.1 wt%) and above (0.5 wt%), with varying MWCNT:GN mix ratios. The hybrid epoxy systems exhibited remarkable electrical performance, attributed to the π-π bond interactions between the multi-wall carbon nanotubes and the graphene layers dispersed in the epoxy resin matrix. The material's properties were characterized through dynamic mechanical and thermal analyses over a wide range of temperatures. In addition to excellent electrical properties, the formulated hybrid systems demonstrated high mechanical performance and thermal stability. Notably, the glass transition temperature of the samples reached 255 °C, and high storage modulus values at elevated temperatures were observed. The hybrid systems also displayed thermal stability up to 360 °C in air. By comparing the mechanical and electrical performance, the formulation can be optimized in terms of the electrical percolation threshold (EPT), electrical conductivity, thermostability, and mechanical parameters. This research provides valuable insights for designing advanced epoxy-based materials with multifunctional properties.

Remediation of environmental toxicants using carbonaceous materials: opportunity and challenges

Adsorption and photocatalytic properties of carbonaceous materials, viz., carbon nanotubes (CNTs), fullerene, graphene, graphene oxide, carbon nanofiber nanospheres, and activated carbon, are the legitimate weapons for the remediation of emerging and persistent inorganic/organic contaminants, heavy metals, and radionucleotides from the environment. High surface area, low or non-toxic nature, ease of synthesis, regeneration, and chemical modification of carbonaceous material make them ideal for the removal of toxicants. The research techniques investigated during the last decade for the elimination of environmental toxicants using carbonaceous materials are reviewed to offer comprehensive insight into the mechanism, efficiency, applications, advantages, and shortcomings. Opportunities and challenges associated with carbon materials have been discussed to suggest future perspectives in the remediation of environmental toxicants.

The Usefulness of Nanotechnology in Improving the Prognosis of Lung Cancer

Lung cancer remains a major public health problem both in terms of incidence and specific mortality despite recent developments in terms of prevention, such as smoking reduction policies and clinical management advances. Better lung cancer prognosis could be achieved by early and accurate diagnosis and improved therapeutic interventions. Nanotechnology is a dynamic and fast-developing field; various medical applications have been developed and deployed, and more exist as proofs of concepts or experimental models. We aim to summarize current knowledge relevant to the use of nanotechnology in lung cancer management. Starting from the chemical structure-based classification of nanoparticles, we identify and review various practical implementations roughly organized as diagnostic or therapeutic in scope, ranging from innovative contrast agents to targeted drug carriers. Available data are presented starting with standards of practice and moving to highly experimental methods and proofs of concept; particularities, advantages, limits and future directions are explored, focusing on the potential impact on lung cancer clinical prognosis.

Molecular and Macromolecular Interactions of Carbon-Based Nanostructures

The interactions of molecules and macromolecules with carbon nanostructures such as carbon dots, carbon nanotubes, graphene, graphene oxide, and fullerenes, have been stimulating the interest of the researchers working on the preparation, functionalization, properties and applications of carbon-based nanomaterials [...].