Current Nanoscience - Volume 19, Issue 6, 2023

Background: Dihydropyrimidinones are an essential component of heterocycles due to their useful attributes, such as calcium channel blockers, anti-inflammatory agents, anti-neoplastic agents, anti-bacterial agents, anti-hypertensives, , and, anti-virals. Objective: Synthesis of Fe3O4@SiPr@vanillin@TGA MNPs and their structure and morphology determination by FT-IR, VSM, EDX, XRD, TEM, FE-SEM, Zeta potential, and TGA. Methods: A synthetic mixture of aldehydes, acetophenone, urea, H2O and Fe3O4@SiPr@ vanillin@ TGA MNPs, were stirred at room temperature to establish the appropriate and optimum reaction time. Results: An efficient and greener method for the synthesis of arylpyrimidinones using Fe3O4@SiPr@vanillin@TGA MNPs in aqueous medium has been accomplished. Conclusion: Higher yields, simpler handling, ease of separation and recycling of the magnetic catalysts, and following the green chemistry tenets for waste minimization and exploitation of abundant natural materials are some of the key features of this process. The anti-bacterial activity of compounds 4a-n and 6a-e were evaluated, and all four bacteria studied were affected by the synthesized compounds.

Photoelectric catalytic water splitting for hydrogen production is considered a promising method for hydrogen production, which can convert clean and renewable solar energy into sustainable and pollution-free hydrogen energy. An in-depth understanding of the relationship between the properties and functions of photocatalytic materials can help design and prepare efficient photodegradable water systems. Among them, α-Fe2O3 has a suitable band gap, can absorb visible light below 600 nm, and has the advantages of abundant raw materials high stability, and has become one of the most promising photoelectrode materials. However, as a photoelectrode material, α-Fe2O3 has the shortcomings of short photogenerated hole diffusion distance, low oxidation kinetics, poor conductivity, ease to be corroding, and so on, resulting in a very low photoelectric conversion efficiency, which limits its application in the field of photoelectric catalysis. This paper reviews the research progress of α-Fe2O3 as a photoanode. Firstly, the principle of photoelectric catalytic water splitting for hydrogen production and the main preparation methods of α-Fe2O3 photoanode is described; Secondly, the research work on modification of α- Fe2O3 photoanode by morphology control, element doping, construction of the heterojunction, surface modification and thermal excitation assisted effect in recent years is introduced. The photochemical performance of α-Fe2O3 photoanode is enhanced by improving the photocurrent density and the transfer of photo-generated carriers.

Recently, there has been a significant increase in the rate and amount of pollutant discharge into the environment. This is extremely worrisome to the human population, especially as it is envisaged to reach 10 billion in the next 40 years. The traditional methods applied for pollutant abatement and recycling exhibit inefficiency and environmental unfriendliness because they cannot effectively transform these pollutants into non-noxious states. Recently, microorganisms and nano-based materials are emerging as highly efficient and eco-friendly alternatives for managing, reducing, and decontaminating pollutant wastes or effluents in the environment. The biosynthesis of these materials has motivated research into developing cheaper, green, and more sustainable yeast, algae, fungi, and bacteria-biogenic nanoparticles, which could be used to clean up heavily contaminated environments. This review evaluates the application of microorganisms (yeast, algae, fungi, and bacteria) with nanomaterials as biogenic nanoparticles to clean up environmental pollutants. The environmental and health hazards associated with the fate of the biogenic nanoparticles, and some legal regulations, are also highlighted. The commercialization of nanomaterials and their possible global application are also documented. Future recommendations were proffered.

COVID-19 spread rapidly around the world in 18 months, with various forms of variants caused by severe acute respiratory syndrome (SARS-CoV). This has put pressure on the world community and created an urgent need for understanding its early occurrence through rapid, simple, cheap, and yet highly accurate diagnosis. The most widely adopted method as of today is the real-time reverse-transcriptase polymerase chain reaction. This test has shown the potential for rapid testing, but unfortunately, the test is not rapid and, in some cases, displays false negatives or false positives. The nanomaterials play an important role in creating highly sensitive systems, and have been thought to significantly improve the performance of the SARSCoV- 2 protocols. Several biosensors based on micro-and nano-sensors for SARS-CoV-2 detection have been reported, and they employ multi-dimensional hybrids on sensing surfaces with devices having different sizes and geometries. Zero-to-three-dimension nanomaterial hybrids on sensing surfaces, including nanofilm hybrids for SARS-CoV-2 detection, were employed with unprecedented sensitivity and accuracy. Furthermore, the sensors were nanofluidic and mediated high-performance SARS-CoV-2 detection. This breakthrough has brought the possibility of making a biosystem on a chip (Bio-SoC) for rapid, cheap, and point-of-care detection. This review summarises various advancements in nanomaterial-associated nanodevices and metasurface devices for detecting SARS-CoV-2.

The management of infectious diseases is one of the major public health challenges of the 21st century. Mutation of the microbes, biofilm formation, and other structural-morphological behaviors have resulted in pathogens acquiring multi-drug resistance. The development of advanced materials that can provide long-lasting and effective protection against harmful microbes is becoming a need of the hour. Biocompatibility, efficient microbial inactivation, thermal and chemical stability of nanomaterials help to reduce the excessive use of antibiotics and, thus, to overcome antimicrobial resistance. Metal and metal oxide nanostructures, graphene, carbon dots, and other two-dimensional materials exhibit excellent antimicrobial properties. This review provides a comprehensive overview of antibacterial mechanisms and factors that help to inactivate the bacteria by nanomaterials. It also points out the enhanced antibacterial behaviors of the modified nanomaterials for future research concerns.

Nanomaterials are a promising and popular research topic for many scientists. Nanodiamond is a branch of nanotechnology in nanoscience. Nanodiamond is a newly emerging type of nanoparticle because of its small size, i.e., 3-4 nm size and shape, and a wide variety of applications such as bioimaging, gene therapy, and new targeted drug delivery for various drugs. Bio applications must meet a number of requirements, such as being safe and effective. In the past, nanodiamond was made in a number of ways, such as by detonation, laser ablation, high pressure and high temperature (HPHT), and explosives. In this review, we cover the following: introduction, features, types, synthesis, future prospects, and application.

Nanocomposites have become a promising approach for drug delivery in the pharmaceutical field due to several benefits and current research development. Polymer nanocomposites (PNCs) are blends of nanomaterials and polymers with at least one-dimensional structure and one component in the sub-100 nm range. By incorporating nanoparticles into the polymer matrix, it is feasible to create a new class of given characteristics. Nano-clay (a type of nanocomposite) is mainly used for the controlled release of therapeutics in various disease conditions. Nanocomposites are promising drug delivery systems due to several advantages, including surface and rheological characteristics. Considering physical and chemical properties, nanocomposites are divided into two different components. Polymer-fabricated nanocomposites are potentially used in multi-particulate systems, which results in a controlled drug release profile with improved mechanical integrity. Nanotechnology-based drug delivery nanocomposites offer an improved half-life, greater biocompatibility, minimum immunogenicity, site-specific targeting, and avoid membrane barriers. Specifically, one-dimensional (1D) nanocomposites show promising responses in theranostics due to improved surface area-to-volume ratios that offer specific targeting, improved encapsulation efficiency, and susceptibility to biomolecules.

Background: Wound healing remains a challenge that has not yet been solved. Researchers are more interested in gold nanoparticles (AuNPs) than other nanoparticles because of their size-related chemical, electrical, and magnetic properties that may be useful in biological applications. Due to their antioxidant, anti-inflammatory, antibacterial qualities, and their capacity to destroy free radicals, AuNPs are also advantageous in lowering inflammation and promoting quicker wound healing. Method: In this study, we analyzed all pertinent papers up to April 2021 to study the impact of AuNPs on the wound healing process in animal experiments based on scientific data, as wound healing is still one of the most significant medical difficulties. Based on the keywords "Gold, Nanoparticles, and wound healing," we carried out a systematic evaluation of the literature in PubMed, Ovid Medline, Google Scholar, Scopus, and Web of Science databases. Result: This analysis shows that in all 13 studies reviewed, AuNPs significantly accelerated wound healing, decreased wound size, and produced complete epithelialization. Discussion: AuNPs reduced inflammatory factors at the location of the lesion. Additionally, groups exposed to AuNPs showed an increase in connective tissue as well as an increase in the deposition of collagen in the wound. Different events such as the production of hair follicles, angiogenesis, antioxidant, and antibacterial actions of AuNPs have also been observed in the healing process of wounds. AuNPs are auspicious substances that may offer a therapeutic option for treating wounds. Conclusion: To validate these results, however, an additional large sample of experimental human research is required.

Background: Nanobiotechnology is a cutting-edge field that is revolutionizing the way we produce and utilize nanoparticles. With bacteria becoming increasingly resistant to traditional antibiotics, researchers are exploring new ways to synthesize antimicrobials. Objective: The aim of this study was to investigate the biosynthesis of different forms of silver nanoparticles using different biological methods from Microcystis sp. to be used as an antimicrobial agent. Methods: We employed the direct strain powder method, ethanolic extract pellets, and ethanolic extract. Then a combination of analytical techniques was used to characterize the properties of nanoproperties. Finally, we evaluated the antimicrobial activity of the AgNPs against a panel of bacteria and fungi. Results: AgNPs were found in various forms, such as cubic, spherical, and rod shapes. UV-Vis detected a peak at 420 nm, and SEM identified the AgNPs with bio-capped layers ranging from 40-130 nm. The antibacterial test revealed that the pellet method produced the most effective AgNPs, specifically against Gram-positive bacteria such as Staphylococcus sp. with a clear zone of 32 mm, while the larger cubic AgNPs produced by the powder method were less effective as antibacterial agents. Conclusion: This study demonstrates that AgNPs can be produced using Microcysts sp. as a reducing and capping agent; furthermore, they are produced in different shapes as cubic, spherical, and rod shapes. Besides that, cubic nanoparticles are more effective in killing germs than spherical ones. The results of this study will help to improve our understanding of the mechanisms of AgNPs biosynthesis and pave the way for the development of new and more effective antimicrobial agents.

Background: The coalescence of Au nanoparticles embedded in the silica gel matrix was observed by E-beam irradiation in a transmission electron microscope. Methods: It was examined that interparticle spacing between nanoparticles was reduced after incorporation into the matrix and particles came close to each other. TEM studies have shown that during E-beam irradiation ~13 nm Au nanoparticles contacted with each other along with the shrinkage of the silica aerogel or as well as the removal of surfactant layer, and transformed into different shapes of particles such as dumbbell and chain-like particles as per the interparticle gap. Results: This nanoparticle-aerogel matrix has the potential for applications in sensing, nonlinear optics, and catalysis. Conclusion: This work enhances the understanding of the role of silica aerogel and E-beam irradiation in directing the coalescence of nanoparticles.