Current Nanoscience - Volume 19, Issue 5, 2023

Over the past few years, nanoparticles have been widely used in therapeutic applications. It is well acknowledged that nanoparticles have improved the shortcomings of conventional treatments. The advantages and drawbacks of inorganic nanocarriers such as metal nanoparticles and quantum dots have been extensively studied. Although carbon nanotubes have been touted as a prominent medication delivery method, their physicochemical characteristics, such as low water solubility, limited circulation time, etc., restrict their use. Compared to hard matter tubes like carbon and other inorganic matter, organic nanotubes have better physiological properties such as improved blood stability, longer circulation time, high serum solubility, etc. The current study focuses on recent developments in the use of organic nanotubes for drug delivery and the utilization of their structural features. The soft, organic material that builds up these nanotubes has a synergistic effect on biocompatibility and lowers cytotoxicity thus proving suitable for the potential use as drug delivery carrier. The goals of this review are to identify the characteristics that support the creation of new drug delivery systems and to shed light on current advancements that have been reported in the literature. The paper also includes discussion of the difficulties in using these organic nanotubes for applications in drug delivery as well as the potential for future research in this field.

Surface-enhanced Raman Scattering (SERS) is a sensing method based on inelastic scattering of a laser beam by a reporter molecule absorbed on a plasmonic substrate. The incident laser beam induces a localized-surface plasmon resonance in the substrate, which generates an oscillating electromagnetic field on the substrate dielectric surface. Under the influence of this field, the reporter molecule absorbed on the plasmonic substrate starts to vibrate, causing inelastic scattering of the laser beam. The laser-induced electromagnetic field is also the main contributor to the enhancement observed in the intensity of the scattered light. Plasmonic substrates are nanostructured surfaces often made of noble metals. The surface enhancement of a plasmonic substrate is determined primarily by factors related to the substrate’s nano-architecture and its composition. SERS-based labeling has emerged as a reliable and sophisticated anti-counterfeiting technology with potential applications in a wide range of industries. This technology is based on detecting the SERS signals produced by SERS tags using Raman spectroscopy. SERS tags are generally made of a plasmonic substrate, a Raman reporter, and a protective coating shell. They can be engineered using a wide variety of materials and methods. Several SERS-based anticounterfeiting labels have been developed in the past two decades. Some of these labels have been successfully combined with identification systems based on artificial intelligence. The purpose of this review is to shed light on the SERS technology and the progress that has been achieved in the SERS-based tracking systems.

Background: The insatiable need for low-power and high-performance integrated circuit (IC) results in the development of alternative options for metal oxide semiconductor field effect transistor (MOSFET) in the ultra-nanoscale regime. The practical challenge of the device scaling limits the use of MOSFET for future technology nodes. ICs are equipped with billions of transistors whose size must be scaled while increasing performance. As the size of the transistor shrinks for the new technology node, the control of the gate over the channel also reduces, leading to sub-threshold leakage. The non-planar technology is the potential methodology to design the ICs for the future technology nodes. The fin-shaped field effect transistor (FinFET) is the most valuable non-planar technology. High sub-threshold slope, better short channel effect (SCE) control, high current drive strength, low dopant-prompted variations, and decreased power dissipation are the prominent features of FinFET technology. Objective: FinFET is an advanced version of MOSFET in terms of geometrical structure. Therefore, in this review paper, the different geometrical structures, working operations, design challenges, future aspects, and the different configurations of FinFETs are presented. The performance of the different configurations of a 1-bit full adder is evaluated and compared. Methods: An overview of FinFET evolution from the planar MOSFET, along with its architecture supported by the requisite equations, is presented in the paper. Besides this, it also gives an insight into the circuit simulation using the FinFETs for the process voltage temperature (PVT) variations, width quantization, design challenges, and the future of FinFETs. A comparative study of FinFET-based 1-bit full adder using various techniques is done to compute and compare the leakage power, delay, and power delay product (PDP). Results: The full adders using FinFETs show less leakage power and PDP. The AND-OR logicbased hybrid full adder using FinFETs shows the least energy consumption per switching. Fin- FET-based gate diffusion input adder shows a 74 % reduction in dynamic power compared to the full adder using MOSFET technology. The low power FinFET-based full adder shows a 54.16 % reduction in leakage power compared to the MOSFET-based full adder. The results signify the effect of multi-gates in curbing the leakage power dissipation. Conclusion: MOSFET faces the practical challenge of device scaling and SCEs at lower technology nodes. It initiates the multi-gate technology for future system generation. FinFET has the capability to design low-power and high-performance circuits in an ultra-nanoscale regime. The geometrical structure of FinFET plays a key role to improve the performance metrics in an ultrananoscale regime.

For the treatment of brain illnesses, there is growing interest in nose-to-brain drug administration. Other, more traditional methods of crossing the blood–brain barrier (BBB) are ineffective. As a result, the therapeutic concentration in the brain cannot be achieved, and the reaction is inadequate. Intranasal medication delivery is one intriguing technique for avoiding first-pass metabolism and bypassing the blood-brain barrier. It lowers medicine doses while reducing systemic side effects. Compared to conventional drug delivery platforms, a nanoparticulate drug delivery method allows for greater penetration via the nasal route. It is better to make the nanoparticles for nose-to-brain administration when a good carrier (polymers) is used. This review focuses on the many processes for creating polymeric nanoparticles, strategies and tactics for improving nose-tobrain drug delivery efficiency, and nanoparticle characterization. The use of the nose-to-brain drug delivery platform is being explored using a variety of nanoparticles created by researchers for the treatment of brain illnesses.

Nanoparticles are well-established carriers for targeted delivery of bioactive polymeric nanoparticles (PNPs). They have attracted significant attention from pharmaceutical scientists globally due to their wide range of applications in the medical field. The encapsulation of drugs into the nanoparticles offers several unique characteristics leading to prolonged circulation, improved drug localization, and thus enhanced drug efficacy. It also provides a better understanding of the molecular basis of the disease. Nanoparticles allow efficient maintenance of medication cycles at the target site, with less exposure to normal cells and thus decreasing the rehabilitation period. Despite extensive developments in the field of nanotechnology, specifically in drug delivery, only a few nanotechnology- based products are currently available in the market. Thus, further advanced exploration is necessary to make nanoparticles useful for the betterment of mankind. This review is focused on recent advancements in pharmaceutical nanotechnology with special emphasis on polymers used for the preparation of PNPs and their emerging applications in tumor-targeting. This manuscript also highlights the recent patents disclosing PNPs for tumor targeting.

To cope with environmental issues, scientists strive to develop innovative materials and methods. Bismuth vanadate (BiVO4) has attracted attention because of its significant characteristics like low toxicity, corrosion resistance, photo-stability, narrow band-gap, and ability to provide better efficiency invisible light. However, fast recombination of charge carriers limits its photocatalytic activity. Many researchers have improved BiVO4 properties by metal doping and coupling with other semiconductors to improve charge separation and photocatalytic activity. This review addressed the recent improvement in BiVO4 structural modification by doping and composite formation using metal and non-metals and compared the efficiency with pure one. In addition, BiVO4 synthesis and application are also extensively discussed, such as dye degradation, water splitting, and water purification. This review can be beneficial for researchers and those interested in exploring and evolving BiVO4-based material as an efficient photocatalyst.

Background: Metronidazole is widely used due to its clinical excellence in treating systemic or local infections caused by anaerobic bacteria. However, it is easily soluble in water, not easy to biodegrade and adsorb and stays for a long time in environments, causing great harm to human health and food safety. Therefore, it is important to choose highly selective and sensitive methods for metronidazole content determination in environments. In this paper, the edible fungus Boletus speciosus was used as the carbon precursor to successfully prepare carbon dots by one-step hydrothermal method, and were used to analyze metronidazole. Methods: Characterization of the prepared carbon dots from B. speciosus (Bs-CDs) were studied by Transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray Diffraction. Results: The linear equation was y=0.06231+0.01099x (R ²=0.9970) with a metronidazole concentration of 2.5~50 μM, and the detection limit was 71 nM. The fluorescence quenching mechanism of Bs-CDs detecting metronidazole belonged to the internal filtration effect. Bs-CDs were applied to detect metronidazole in actual water samples, presenting good sensitivity and a high recovery rate (97.0~106.0%). Conclusion: It provides a new idea for applying carbon dots in metronidazole content detection.

Background: Synthesis of spherical silver nanoparticles is mostly reported, but the use of DNA, especially short oligonucleotides, to mediate the production of anisotropic AgNPs is still questioned. Objective: This work aims to use 30-mer oligo(dA) and oligo(dC) (or A30 and C30) to assist the formation of anisotropic AgNPs under blue LED irradiation. Methods: We reported a simple synthesis reaction containing AgNO 3, A30 (or C30), and sodium borohydride, which were exposed to 460 nm LED light for 24 h. The obtained AgNPs were characterized and assayed for antioxidant and antibacterial activities. Results: With exposure to 460 nm LED light, A30 and C30 could mediate the transition from spherical to hexagonal shapes of AgNPs with average sizes of 16 − 18 nm. Analyses of X-ray diffraction and selected area electron diffraction indicated the face-centered cubic crystal structure of AgNPs. A30- and C30-AgNPs exhibited similar antioxidant activities; IC 50of 78.68 ± 0.83 and 73.91 ± 0.46 μg mL ⁻¹, respectively. They also possessed antibacterial activities against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Scanning electron micrographs revealed surface pores and rupture of bacterial cells in response to AgNPs. Conclusion: Oligonucleotides of only 30 residues are shown to assist the generation of anisotropic AgNPs under activation of blue LED irradiation, in which the synthesized AgNPs still exhibited antioxidant and antibacterial activities, suggesting a simple method to synthesize non-spherical AgNPs using short-length DNA.

Background: The study of metallic nanoparticles is important since they present nonlinear optical properties crucial for modern photonic science and technology. Moreover, their mechanical, chemical, and optical properties are different from those presented with respect to volumetric material. Said properties can be adjusted by controlling the size and shape of the studied nanoparticles, and various methodologies have been developed to obtain nanoparticles by chemical and physical means. Methods: Spherical nanoparticles were synthesized by chemically reducing silver nitrate, sodium borohydride, and sodium citrate precursors. Different amounts of silver nitrate were added to the original spherical nanoparticles and then exposed to a green LED light source to convert the spherical nanoparticles to triangular prisms. The changes in the samples were monitored using absorption spectra obtained with a UV-Vis spectrophotometer. The nonlinear refractive index was determined with Z-scan measurements, and a scanning electron microscope was used to observe the silver nanoparticles before and after laser irradiation. Results: The absorption spectra show a band of around 418 nm for the original spherical nanoparticles, which shifted to blue after the irradiation with green LED light. Furthermore, a new band was obtained, centered around 565 nm, which indicates the presence of triangular prisms. From SEM images, it was confirmed that the spherical nanoparticles were transformed into triangular nanoprisms. The non-linear (negative) refractive index depends on the shape and number of nanoparticles; however, using the Z-scan technique caused photo-melting and photofragmentation of the triangular prisms, which was corroborated by SEM images. Conclusion: These results suggest that the shape and amount of AgNPs can be controlled with excess silver ions and irradiation time. In addition, the Z-scan technique causes photo-melting and photo-fragmentation of AgNPs, and their nonlinear refraction index is negative due to thermal origin.