Journal of Applied Sciences and Nanotechnology

Considering the introduction of aptamers as a new generation of analyte identifiers, this class of materials can be used in diagnostic systems because aptamers are easier to produce, more sensitive, higher accuracy, less sensitive to environmental factors, easier to handle and can be used. A particular type of aptamer that has a sequence rich in guanine base can create a unique nanostructure called G-quadruplex. The creation of this structure gives the aptamer an enzyme property so that it can act like an enzyme in the vicinity of it, oxidise a chromogenic substrate and produce a coloured signal. The main way to produce aptamers is a laboratory technique called SELEX (Systematic evolution of ligands by exponential enrichment), in which a mixture of different oligo libraries near the target analyte creates aptamers in several consecutive cycles. The aim of this study was to introduce a novel approach for obtaining DNA aptamers for detecting a ligand such as an aflatoxin M1 in bioinformatically manner in replacing SELEX for obtaining the specific oligo aptamers against aflatoxin M1. For this purpose, the selected oligoaptamers' structures were predicted using molecular simulators and bioinformatic techniques. The results of these molecular simulations suggested G-quadruplex aptamers with a suitable affinity for binding to aflatoxin M1 in colourimetric assays.

This study describes the relativistic q-Gaussian laser beam's stimulated Raman scattering (SRS) in an unmagnetized plasma. Moreover, the influence of the pump laser's relativistic self-focusing on the SRS process has been investigated. Using variational theory, we derived analytical solutions to the coupled nonlinear wave equations describing the pump, EPW, and scattered waves. The resulting equations were numerically solved to see the impacts of laser and plasma characteristics on the dynamics of the pump beam and its influence on the power of scattered waves. The power of the scattered wave was observed to be significantly altered via the self-focusing action of the pump beam, where when the effect of self-focus increases, it leads to an increase in the effect of stimulated Raman scattering. The stimulated Raman scattering yield is investigated based on the intensity of the laser beam and plasma. The main finding is that as q increases, the SRS yield rises, and as the intensity of the laser beam and plasma density increase, the SRS yield also increases. The scattering of the self-focused beam occurs at a greater distance than the beam of the pump due to the relatively diminished level of scattered power. The value of the integrated reflection increases with the increase of q and the growth rate.

Tin oxide (SnO2) nanoparticles were synthesized via a facile chemical precipitation route using tin chloride (SnCl2•2H2O) as precursor and ammonia as precipitant. The as-synthesized nanoparticles were subjected to post-calcination at 300°C, 400°C and 500°C and thoroughly characterized by advanced techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. XRD patterns revealed the formation of a tetragonal SnO2 crystalline phase with average crystallite sizes of 11.9 nm, 13.9 nm, and 17.2 nm for the samples calcined at 300°C, 400°C and 500°C respectively. SEM micrographs demonstrated agglomerated and irregular morphology of the calcined SnO2 nanoparticles. FTIR spectra confirmed the presence of characteristic Sn-O and O-Sn-O vibrational modes in the calcined SnO2 samples. The antibacterial activity of the synthesized nanoparticles was evaluated against model Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains by standard zone of inhibition assays. The SnO2 nanoparticles exhibited excellent antibacterial activity due to their high specific surface area. A systematic increase in the inhibition zone diameter was observed with a decrease in the crystallite size of SnO2 for both bacterial strains, suggesting an inverse relationship between crystallite size and antibacterial behaviour. The present work demonstrates a simple, eco-friendly synthesis of antibacterial SnO2 nanoparticles with controlled crystallite size by tuning the calcination temperature.

The use of plant extracts as a bio-reducer for the synthesis of silver nanoparticles has attracted attention due to its rapid, ecological, non-toxic and economical protocol. The aim of this study was to investigate the possibility of synthesizing silver nanoparticles using Cymbopogon citratus leaf extract, and characterizing them by Ultraviolet-visible spectroscopy, X-ray Diffraction and X-ray Fluorescence in order to determine their size and composition, as well as to evaluate them in-vitro bioactivity on selected models. The results of this study show that silver nanoparticles were successfully synthesized, with a size of 29.49 nm. The silver nanoparticles showed bactericidal activity against all three types of bacteria (E. coli ATCC 25922, S. aureus ATCC 25923, and P. aerugunosa ATCC 27853) at the minimum inhibitory concentration (MIC=31.25 μg/mL), larvicidal activity against Anopheles larvae and reasonable antioxidant properties. All these results demonstrate the biopharmaceutical potential of these new products. These nanoparticles, synthesized from plant extracts, could be a promising solution for the treatment of a number of diseases, including malaria, bacterial infections and diseases caused by oxidative stress.

Mannich base is a versatile compound that can be easily modified to introduce different functional groups, allowing for the creation diverse selection of items with varying features. Additionally, the Mannich reaction is a valuable tool in organic synthesis, due to the fact it provides an effortless and efficient approach for synthesizing C-N bonds. Overall, The Mannich base and even its derivatives are essential in many aspects of chemistry and its complexes are in the pharmaceutical industry. Studies have revealed that it shows good anti-cancer, anti-mycobacterial, remarkable anti-HIV, anti-tubercular, anti-convulsant, anti-fungal, antiviral, antitumor, cytotoxic activities and in industrial applications such as in the creation of polymers, surface activity agents, deter gents and resins. The presence of the basic Mannich sidechain has shown marked antimalarial, anti - inflammatory, analgesic and anti - microbial activities. These compounds have also been shown to inhibit corrosion, as well as antioxidant and reducing agents. This review article shows the definition, importance and different applications of Mannich base ‎ligands with transitional metal. These complexes exhibit potent anti-microbial, antiviral, and anti-cancer activities, showcasing their potential in pharmaceutical research and drug development. Moreover, the luminescent properties of Mannich base metal complexes have been harnessed for applications in optoelectronics and sensing. Their tunable emission profiles make them suitable candidates for various sensing platforms and light-emitting devices Mannich base metal complexes.

Graph Theory is a discipline of mathematics with numerous outstanding issues and applications in various sectors of mathematics and science. The chromatic polynomial is a type of polynomial that has valuable and attractive qualities. Ehrhart's polynomials and chromatic analysis are two essential techniques for graph analysis. They both provide insight into the graph's structure but in different ways. The relationship between chromatic and Ehrhart polynomials is an area of active research that has implications for graph theory, combinatorial, and other fields. By understanding the relationship between these two polynomials, one can better understand the structure of graphs and how they interact. This can help us to solve complex problems in our lives more efficiently and effectively. This work gives the relationship between these two essential polynomials and the proof of theorems, and an application related to these works, the model Physical Cell ID (PCID), was discussed.