Current Nanoscience - Volume 20, Issue 1, 2024

Background: Graphene and its derivatives have been widely used in modern electrochemical- related technologies due to their versatile structure, tunable conductivity, and large specific surface area. However, there is a need to provide the latest global literature overview in this field.Methods: In this study, we reported a literature overview of current developments in the applications of graphene in energy conversion and storage by electrochemistry. In this overview, 1285 pieces of literature were retrieved and analyzed based on the web of science core database using bibliometric tools.Results: The major contributing countries are China and the United States. The most widespread fields are the development of novel nanomaterials and catalysts and approaches to improve the electrocatalytic performance of batteries and supercapacitors. The hotspots of current research include sodium-ion batteries, lithium-sulfur batteries, sulfur-doped electrodes, and the study of high-efficiency electrocatalysts for oxygen and evolution reactions.Conclusion: With the continuous development in this field, scientists are committed to continuously improving the performance of energy equipment. The applications of graphene-based materials for electrochemical energy conversion and storage are briefly summarized. The challenges and prospects for future research in this field are also discussed.

Nanomaterials often show very different sizes, shapes, and stability properties. They also facilitate electron transfer and can be easily modified with chemical ligands and biomolecules. These properties, combined with the ease of miniaturizing nanoscales and their application to sensing devices, make nanomaterials well suited for essential chemical/biochemical sensing applications.Nanomaterials are superior materials not only due to their structural properties but also their functional properties. Using various methods makes it possible to change the available and stack properties.Nano-sized materials are preferred in modern technological systems because they have a large surface area and different optical and electronic properties.In this study, electrochemical biosensor applications based on sensors modified with various nanomaterials were evaluated in terms of analytical parameters, such as detection limit, linear range, and features, such as easy fabrication, storage stability, and reproducibility. Besides, the advantages of using nanomaterials were examined under 6 different headings as enzyme biosensors, immunosensors, nucleic acid sensors, cell, phage, and aptasensors.

This overview describes the synthesis, characterization, and application of different carbon dots hybrid nanostructures obtained by chemical interaction between nanomaterials or nanomaterials bonded to another material, i.e. silicon (SiO2/Carbon dots-N), reduced graphene oxide (rGO/Carbon dots), multiwalled carbon nanotubes (MWCNTs/Carbon dots), nano magnetite (Carbon dots/Fe3O4), reduced graphene oxide and gold nanoparticles (rGO/Carbon dots/AuNPs), copper oxide (CuO/Carbon dots), and Carbon dots/Metallic NPs that were employed in the development of electrochemical (bio)sensors. The formation of different carbon dots hybrid nanostructures has been characterized by X-ray diffraction (XRD), Raman and ultraviolet- visible spectroscopy, atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM), and electrochemical techniques. These carbon dots hybrid nanostructures have been used to modify the surface of glassy carbon and screen-printed electrodes and to determine various analytes, i.e., dopamine, uric acid, paracetamol, ephynefrin, dihydroxybenzenes, pesticides, endocrine disruptors, NADH, and other substances in real samples.

Carbon nano-onions, a family of carbon nanomaterials, consist of multiple concentric fullerene- like carbon shells which are highly defective and disordered. Due to their unique physicochemical properties, such as high conductivity, high surface area, biocompatibility, thermal stability, and others, they are promising nanomaterials for different electrochemical applications. In this sense, this review outlines the synthetic methods available to afford carbon nano-onions in their pristine, functionalized (covalent and non covalent) and doped forms and their use in energy storage, electrocatalysis and sensing. Particularly, we review the performance and properties of carbon nano-onions as electrode materials for supercapacitors, electrocatalysts in different reactions for fuel cells, and electrode materials for sensors. In the last decade, as we will discuss, scientists have found that functionalized and doped carbon nano-onions have better electrochemical properties than pristine carbon nanoonions, such as specific capacitance, surface wettability, energy power, adsorption on an electrode surface, and charge delocalization, among others.

With so many of our daily activities related to electricity, from telecommunication to laptops and computers, the use of electric energy has skyrocketed in today's technology-based world. Energy output must rise to meet rising energy demand. Still, as fossil fuels are running out, we must turn to more renewable energy sources, particularly solar energy, which can be harnessed and converted to electricity by solar-powered cells. The issues, however, are brought about by the sunlight's unpredictable energy output. The energy produced by solar cells should therefore be stored using energy storage technologies. This notion led to the development of the photo-supercapacitor, a device that combines a solar cell with a supercapacitor to store the energy generated by the solar cells. However, recently researchers developed light-responsive materials for supercapacitors that could be used directly as electrode materials and deposited on various transparent and conductive substrates. Such light-responsive supercapacitors could be operated directly by shining solar light without using any solar cell. A light-responsive supercapacitor's efficiency is primarily influenced by the active materials used in its electrode fabrication. The main components of high-energy conversion, which improves a light-responsive supercapacitor's performance and shelf life, are photoactive materials, counter electrodes, compatible electrolytes, and transparent substrate performances. Furthermore, light-responsive supercapacitors are cutting-edge and promising energy storage devices that can self-charge under light illumination by converting light to electrical energy and storing it for later use. They are considered a novel approach to energy issues in electrical transportation, electronic equipment, and on-chip energy storage devices. Thus, this review paper opens up an avenue for the direct utilization of photoactive nanomaterials for electrochemical energy storage and demonstrates the substantial potential for the fabrication of advanced light-responsive supercapacitors. This study also covers the fundamentals of how this exciting field works, the historical trajectory of how far it has come, and the promising prospects for its future.

Cancer is one of the most widespread life-threatening diseases, and among different types of cancers, breast cancer is the major disease affecting many women worldwide.Background: Conventional chemotherapy using anticancer drugs has many drawbacks, like poor water solubility, poor bioavailability, rapid relapse, non-specific selectivity, effect on normal tissues, and rapid drug resistance. Thus, over the last few years, immense efforts have been made to fabricate nanotherapeutics that will release drugs in response to stimuli.Objective: Nanotherapeutics based on graphene quantum dots have been acknowledged with much gratitude in the bioscience field and investigation applications because of their distinguishing chemical and physical properties, such as medicine delivery, biosensors, and bioimaging for the advancement invention of disease.Conclusion: This paper analyzes the potential applications of graphene quantum dots for the modified and desired release of antitumor drugs. Also, it shows graphene quantum dots' capability to functionalize in the companionship of hyaluronic acid that operates regarding cancer cell directing matrix in bioimaging and multimodal therapy.

Background: Tumors are increasingly heterogeneous throughout the process of their growth, producing a mixed-cell community with a range of molecular features and susceptibility to therapies. Nanotechnology has shown tremendous potential in diagnosing and treating solid tumors.Objective: Most cancer-related deaths are attributed to the lack of early detection and effective treatment. Its early diagnosis helps overall survival and health-related quality of life in patients identified with cancer. Nanosystems are favorable for endocytic intracellular retention, high drug loading, enhanced therapeutic efficacy, greater drug-circulation time, superior dose scheduling for patient compliance, and site-specific targeting. Integrating nanosystems into biomedical applications will also reintroduce medicines that are no longer used in clinical practice because of certain drawbacks and help the identification of new active medicines with their sub-optimal kinetic profiles. This review provides insights about the targeted cancer treatment based on active targeting (folate receptor-α, heat shock protein, receptor 2 for epidermal human growth factor, and CD44 receptor) and various nano device-based systems.Methodology: The highly relevant articles were retrieved using various search engines, including Web of Sciences, Science Direct, Scihub, PubMed, Scopus, PubChem, Google Scholar, and others. The keywords and phrases used for the search are "liposomes," "quantum dots," "nanoparticles," "nanocrystals," "photodynamic therapy," "passive targeting," "active targeting," "nanomaterials," "nanotechnology," "cancer," "nanotheranostics" and several others. In this review, we briefly introduced the concept of the contribution of nanotheranostics to cancer therapy with their recent findings. We also discuss the role of biosensor-based nanosystems in cancer.Conclusion: This review addresses nanotechnology's exciting role in identifying, imaging, and managing solid tumors and their immense potential.