Corrosion prevention has been a global phenomenon, particularly in metallic and construction engineering. Most inhibitors are expensive and toxic. Therefore, developing nontoxic and cheap corrosion inhibitors has been a way forward. In this work, L-arginine was successfully grafted on chitosan by the thermal technique using a reflux condenser. This copolymer was characterized by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The corrosion inhibition performance of the composite polymer was tested on mild steel in 0.5M HCl by electrochemical methods. The potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results were consistent. The inhibition efficiency at optimum concentration rose to 91.4%. The quantum chemical calculation parameters show good properties of the material as a corrosion inhibitor. The molecular structure of the inhibitor was subjected to density functional theory (DFT) to understand its theoretical properties, and the results confirmed the inhibition efficiency of the grafted polymer for corrosion prevention.

The stem-bark of Prosopis africana commonly known as African mesquite or Iron tree, has been utilized in traditional medicine across Africa for its purported medicinal properties. This plant specie belongs to the Fabaceae family and is a native to Sub-Saharan Africa. Its bark has been traditionally used to treat various ailments, including malaria, fever, gastro-intestinal disorders and inflammatory conditions. This study provides a comprehensive profile of the methanolic crude extract obtained from the stem bark of Prosopis africana using LCMS molecular networking analysis and 1H-NMR. A total of 47 metabolites were putatively identified in both positive and negative ion modes by the LCMS, while the 1H-NMR spectroscopy validates the identities by providing some insights in their structures through assigning the chemical shifts that corresponds to their multiplicities. The 19 metabolites from the positive ionization were further classified as peptides, phenols, fatty acids, polyketides, steroids, lipids, amino acids, quinones, flavonoids, azaspiranes, fatty acyl glycines and acyl amino acids. On the other hand, the 28 metabolites from the negative ion mode were also categorized into different classes of metabolites which include: 6 alkaloids, 2 phenolic compounds, and four terpenoids. Other categories include: cycloalkene, polyether, triazines, anthraquinone, indole, carboxylic acid derivatives, flavonoid, glycoside and saponin. In addition, more than 26 clusters were also discovered using the MS/MS based molecular networking. The study contributes to the body of knowledge regarding the chemical constituents of Prosopis africana and provides a foundation for further research on its therapeutic applications in natural product-based medicine as metabolomics have never been used on Prosopis africana plant.

In recent years nanoparticles have gained the attention of researchers due to their transition from micro level to nano level which has resulted in interesting changes in their physicochemical properties. These changes are mainly attributed to their small size which leads to an increased surface to volume ratio and quantum confinement effects. Consequently, the objective of this paper is to synthesize and characterize Silicon Dioxide (SiO2) nanoparticles using appropriate standard procedures. Data obtained show that UV-vis analysis of SiO2 has an absorption peak at wavelength 200-300 nm with a ban gap energy of 4.2 eV. These peaks indicate that SiO2 has been formed. The FTIR results revealed the Si-O-Si bonds which indicated the presence of silica, the O-H and H2O are functional groups, and this confirms the presence of SiO2 nanoparticles. The XRD results of analysis, based on the diffraction pattern, demonstrated that the nanoparticles have an amorphous nature, due to their tendency to agglomerate. Also, based on the calculation carried out using Debye-Scherer‟s equation, the SiO2 has the size of 0.0141 nm. The SEM-EDX results, the images at different magnifications revealed that SiO2 nanoparticles form a large-size “combination” (clusters). The presence of oxygen in the EDX result indicates the formation of silica as silicon dioxide.

The evolution of the recent electrochemical biosensors reflects a simplification and enhancement of the transduction pathway. Modification of the transducer with nanomaterials has become increasingly studied with many advantages. In this study,Indium Tin oxide (ITO) electrode was obtained after modification of the ITO coated glass with conducting PAni-Fe3O4 nanocomposites on which antiβ-Amyloid was immobilized on the new electrode for detection of Alzheimer's diseases. Thin film of PAni-Fe3O4 composite was deposited by the electrophoretic technique on an ITO-coated glass plate to serve as a matrix for immobilization of antibody (anti-β amyloid). Electrochemical responses were generated at-200 mV reduction potential. The calibration curve of the immunosensor showed a linear response between 0.5 μg/mL and 2 μg/mL and a detection limit of 0.03 μg/mL. The incorporation of glutaraldehyde as a mediator resulted in a well-oriented antibody immobilization of the capture antibody and consequently enhanced the sensitivity.Response studies of the Anti-β Amyloid /PAni/Fe3O4/ITO bioelectrode have also been carried out. The results of the biosensing studies reveal that this bioelectrode can be used to detect β Amyloid in a wide detection range of 25-500mg/dL with high sensitivity of 3.36 mAmg-1dL and a fast response time of 30 s at pH 7.4. This bioelectrode exhibits a very low value of Michaelis-Menten constant of 1.18mM indicating enhanced interactions between β Amyloid and anti-β Amyloid immobilized onto this nanostructured PAni/Fe3O4 matrix. In conclusion, this immunosensor can be a promising technology for the rapid and convenient detection of β-Amyloid in real serum samples