Current Nanoscience - Volume 17, Issue 6, 2021

Herbal medicine is a significant component of traditional medicine and has been a part of the treatment of many diseases. Asian people are using herbal medicines for decades. Still, the therapeutic efficacy and pharmaceutical application of herbal extracts encounter difficulties associated with many factors, such as poor bioavailability, low solubility, permeability and lack of targeting potential. Hydrogels are a hydrophilic polymeric network and able to permeate a significant volume of fluids. Hydrogels are biologically compatible and can allow for the sustained release of drugs. These have thus attracted the attention of extensive pharmaceutical formulation studies. The present article first provides a general overview of the hydrogel as a professional nanocarrier. Secondly, the relationship between hydrogel properties and carrier efficiency deliberation has been discussed. In the end, the focus is on the latest technological progress over hydrogel-based materials as herbal medicine carriers. The potential application of hydrogel systems as a carrier for herbal bioactive delivery has shown remarkable promise. This study would be helpful for researchers in the relevant field to understand the most recent advancements in the production of hydrogel-based elements as a vehicle for the delivery of herbal drugs.

The imaging speed of atomic force microscope (AFM) is limited by the cantilever mechanical bandwidth, which can be increased by reducing the size of the cantilever. However, the ordinary laser reflection method cannot measure the deflection of a small cantilever. Moreover, some samples are sensitive to light detection and not suitable for the laser reflection method. Therefore, the self-induction probe technology was developed to solve this problem. This article reviews the latest AFM self-induction probe technology and introduces three types of self-induction probes. Firstly, it is introduced that the current self-sensing probes can be divided into piezoresistive type, piezoelectric type and tuning fork type according to the working mechanisms and preparation materials. Then, the latest materials and structures of various self-sensing probe technologies are introduced to improve imaging performance and their applications in various fields. Moreover, compared with traditional laser reflection methods, the self-sensing probe technologies have a simpler structure, take up less space and can be integrated in a large cantilever array and adopted for imaging of photosensitive products. Finally, some prospects of the novel imaging and sample characterization techniques and new applications of atomic force microscopy are also discussed.

Industrial wastewater is one of the by-products of several industries, and it consists of water that requires treatment before it is discharged into water bodies. The presence of toxins in wastewater, such as dyes and heavy metals, is hazardous to human health and requires effective removal to reduce environmental pollution. Industrial wastewater treatment has become a global concern in healthcare and the environment leading to the development of various technologies for the removal of toxins from wastewater. Various processes and technologies, such as advanced oxidation processes, adsorption and membrane technology, show potential in treating industrial wastewater. Another source of toxins in the form of pesticides is harmful to human health, leading to severe health problems. Nanocomposites show potential as efficient adsorbents for the removal of toxins owing to the enhanced adsorption capacity, promising physicochemical properties and high surfaceto- volume ratio due to nanoscale dimension. Nanocomposites are cost-effective and efficient nanoadsorbents for the removal of various toxins. This review focuses on the potential applications of nanocomposites as adsorbents for the removal of toxins like dyes, heavy metals and pesticides from wastewater and biological systems. The use of nanocomposites as efficient adsorbents in the removal of toxins, various isotherm models, and adsorption kinetics applied in the mechanism of adsorption is also discussed in the article. In the near future, nanocomposites may provide a simple, economic and efficient adsorption system for the removal of toxins from wastewater and biological systems.

Graphene is an allotropic form of carbon with a single-layer 2D structure. Graphene’s unique physical and electrochemical properties, such as its large surface area, high conductivity, robust mechanical strength, remarkable thermal conductivity, exceptional biocompatibility, and suitability for functionalization, make it a new research frontier for carbon-based nanomaterials. In this review, we summarize the different aspects of Graphene, that is, its synthesis via two approaches, namely, top-down and bottom-up approaches, and discuss its new derivatives.

The entire world is now in a state of caution since the outbreak of the COVID-19 pandemic. The overwhelmingly high spread and mortality rate due to the SARS-CoV-2 virus has not only made the headlines but also raised alarming concerns for the human community. Applications of nano-biotechnology, along with machine learning, have excellent potential in dealing with serious health issues, mainly in medical science. This review article aims to augment the multidimensional use of silver nanoparticles, especially in the fabrication of textiles and face masks, which could represent a new avenue for prevention. Furthermore, the disinfection of COVID-19, along with other pathogens using silver nanoparticles and machine learning could help in the risk assessment.

Biocatalysts or enzymes have a pivotal role in speeding up most of the biochemical reactions that drives life processes. Although substrate-specific and promising, there are some pitfalls that limit their use for wide application. To counteract the shortcomings, artificial enzymes possessing enzyme characteristics with additional qualities have been devised, and that kick-started in the late 2000s. This review aims to provide an overview of nanozymes, designing concepts, nanomaterials and applications. To begin with, the limitations encountered by natural enzymes and its replacement with nanozymes have been highlighted. Secondly, how nanozymes evolved in due course of time, their classification and engineering strategies have been briefly described. Most importantly, the engineering of nanozymes for improved catalytic activities has also been discussed. A clear distinction between the enzymatic-mimic for various clinical and bioimaging applications has been critically reviewed. With this rapidly emerging technology, there would be a great demand pertaining to scalability, biosafety, catalytic diversity and environmental impacts challenging the futuristic world.

Background: Selenium, an essential micronutrient, has been studied for decades for its anticancer properties. Selenium nanoparticles (SeNPs) have now emerged as an interesting alternative for drug and gene delivery. Aims: We aimed to demonstrate in proof of principle, the potential use of SeNPs in targeted pCMVLuc DNA (pDNA) delivery in vitro. Objective: To chemically synthesize, characterize and evaluate the transgene expression of functionalized SeNPs in five human cell lines. Methods: SeNPs were synthesized via chemical reduction, coated with chitosan (Ch) and a targeting moiety, folic acid (FA). All nanoparticles were characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), UV-vis and Fourier transform infra-red (FTIR) spectroscopy. Nanoparticle:pDNA interactions were assessed using the electrophoretic mobility shift, dye displacement and nuclease protection assays. The MTT and Luciferase reporter gene assays were used to determine cytotoxicity and transgene expression, respectively, in the human colorectal adenocarcinoma (HT-29 and Caco-2), breast adenocarcinoma (MCF-7), oral epidermoid/cervical carcinoma contaminant (KB) and the embryonic kidney (HEK293) cells. Results: Homogenous nanoparticles of 60-70 nm were able to successfully bind, compact and protect the pDNA from enzyme digestion. Low cytotoxicity was observed in all cells, except for the MCF-7 cells, which could be attributed to apoptosis and necrosis. Luciferase gene expression was highest for the targeted nanocomplexes in the folate-receptor rich KB cell line, confirming nanocomplex uptake through folate receptor-mediated endocytosis. Conclusion: This study opens a new avenue for synergistic treatment of cancer, combining selenium’s bioactivity and its carrier potential for therapeutic gene delivery.

Introduction: Silver nanoparticle (AgNP)-based chemical etching is applied to produce silicon nanowires (SiNWs) on monocrystalline silicon. Methods: The effect of etching time on the production of silicon nanowires and on optical and optoelectronic properties was studied. Results: Using this approach, surface recombination velocity (Seff) and the effective lifetime (Τeff) evolution of SiNWs after passivation were improved, and SiNWs obtained in the optimal time of 20 min, exhibited shallow reflection of 1% in the wavelength range of 300–1100 nm. Conclusion: Thus, passivated solar cell-based SiNWs in an HF/HNO3/H2O solution were essential for increasing the efficiency of solar cell-based SiNWs from 9% to nearly 15%.

Objective: Controlled morphological FeCo nanoparticles with different Fe/Co ratios were prepared by a surfactant-free modified chemical reduction process in the water medium. Methods: Polyethylene glycol PEG 200 was used to protect from areal oxidation of FeCo alloy, and a mixture of hydrazine, sodium hydroxide was served as the reducing system in this process. Results: It was found that the shape of FeCo nanoparticles varied from flakes to cubes according to the atomic ratio of the metal precursors. X-ray diffraction (XRD) data showed that the prepared samples with different compositions got a single-phase body-centered–cubic structured FeCo alloy. Scanning Electron Microscopy (SEM) and transmission electron microscopy (TEM) confirmed all sample's atomic ratios and sizes (FeCo cubes with a size of ~130 nm). Conclusion: The vibrating Sample Magnetometer (VSM) measurements reveal that the Fe60Co40 had the highest magnetization of 208 emu/g among all samples.

Background: Electrochemical sensing has been widely used as a glucose sensor. Methods: In the present work, we have investigated the application of nickel ferrite (NiFe2O4) nanoparticles (NFNPs) for dextrose sensing applications. NFNPS were synthesized by using a simple and low-cost probe sonication method (PSM). The structural, optical and electrochemical properties of prepared nanoparticles were measured by using XRD, FTIR and DRS techniques. Results: The PXRD pattern confirmed the formation of inverse spinel structure for NFNPs with a face-cente red cubic (FCC) structure. The diffuse reflectance spectral studies revealed the energy band gap of NFNPs as deduced to be 2.50 eV by using Kubelka-Munk function. The efficiencies in the photocatalytic degradation of Acid Red 88 (AR-88) and Acid Blue 88 (AB-88) dyes were found to be better with 93.45% and 84.45%, respectively. The EIS parameters corroborated the significant reduction in the charge transfer resistance of NFNPs electrode. The sensing of dextrose in acidic solution by using NFNP through carbon paste electrode was successful. Conclusion: The obtained sensing and photocatalytic results revealed that the synthesized NFNPs could be a better electrode material for the detection of dextrose with high electrode reversibility, in addition to its excellent photocatalytic characteristics towards the dye degradation.

Background: Heterostructured nanocomposites have gained massive attention for their catalytic properties lately. A wide array of different visible-light-active photocatalysts (VLAPs) have been extensively studied over the past couple of years to fine-tune the bandgap of various stable semiconductors. Objective: The current investigation reports the sensitization of TiO2 nanoparticles with nano-sized cuprous oxide, a well-studied p-type semiconductor, which has a relatively narrow bandgap ranging between 2.1 eV & 2.6 eV, to obtain a visible light active photocatalyst. Methods: Visible-light-active Cu2O–TiO2 nanocomposite was synthesized using solvothermal technique. The nanocomposite’s structure and size properties were studied using powder diffraction (XRD), and electron microscopy (FESEM and HRTEM). Cu2O-TiO2 nanocomposite was tested on benzene, toluene and chlorobenzene in contaminated water, under UV and under visible light, for effective implementation in photocatalytic degradation of volatile organic contaminants. Results: The said nanocomposite was crystalline and found to be 40–50 nm in size. No apparent change in the crystal lattice of TiO2 was observed due to the introduction of copper ion, and the nanocomposite also retained a high surface area of 76.28 m2/g. The efficiency of the Cu2O-TiO2 nanoparticles degradation was studied both under UV light and under visible. Cu2O-TiO2 nanoparticles achieved 97 – 99% degradation of benzene, 92 – 97% degradation of toluene and 95 – 98% degradation of chlorobenzene in water. Conclusion: The said Cu2O–TiO2 nanocomposite is photo-active and showed an overall 95% degradation within 2 hours of treatment under the visible region.

Aims: Erythrocruorin is considered for a potential application as a Red Blood Cells Substitute. Background: Nanostructured materials such as liposomes and polymeric materials have offered new alternatives that allow the design of systems as potential substitutes for red blood cells. Objective: Functionalized liposomes fabrication and characterization. Methods: The liposomes manufactured with egg yolk lecithin prepared by the extrusion method were functionalized with EfEc and stabilized with polyethylene glycol (PEG) by an absorption method. Results: The nanoplatform has a hydrodynamic diameter of 452.4 ± 24.56 nm; this size provides the ability to avoid problems such as system extravasation, also presents stability (ζ-potential = -30. 06 ± 0.42 mV) and SEM micrographs show a semi-spherical morphology. Also, EfEc showed a peak of fluorescence emission at 449 nm, which allowed us to observe the protein's presence on the surface of the liposomes employing CLSM. Conclusion: In this work, we report the fabrication and characterization of liposomes with EfEc and PEG on their surface. The nanoplatform exhibits physical-chemical characteristics that confer a potential application as a substitute for red blood cells.