Papers by Keyword: Ultraviolet Spectroscopy

Abstract: Studying the spectroscopic properties of nanomaterials and nanoparticles is essential for developing nanomaterial science and nanotechnology. Spectroscopic properties of nanoparticles of biological origin, especially pathogenic nanoparticles such as viruses, became actual after the Covid-19 pandemic, causing economic, human and social harm. Known spectra of the utmost atoms, molecules, and compositions are well used for identification. In this paper, we provide a concise review of the experimental results obtained from advanced spectroscopy techniques by various scientific groups and demonstrate the possibility of using spectra of viruses to detect and identify diseases caused by pathogens. Raman, ultraviolet (UV), and infrared (IR) spectroscopy methods for experimental study of viral materials are considered.

Abstract: An inexpensive and simple approach using ultraviolet-spectroscopy to distinguish vinegar samples was developed. Vinegar samples were diluted with distilled water(water/vinegar was 6/1, v/v), then distilled with rotary evaporator at 45°C. The distilled liquid was introduced into the UV-Vis 2550 spectrophotometer to scan the UV spectrum from 245 nm to 330 nm, distilled water was used as reference solution. Once spectra were collected, principal components analysis (PCA) and artificial neural network (ANN) were employed for the exploratory analysis and the development of classification models, respectively. The criteria for discrimination were various raw materials and the different fermentation process of vinegars. The correct rate of the classification according to the production process was more than 90% and it was 100% according to the raw materials. The ANN model also could be used to class vinegar samples according to the raw materials, the correct rate was 80.95% in this research.

Abstract: Hydroxyapatite (HAP) was synthesized in Triton X-100 microemulsion and was characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS). Particle size analysis results showed that the particles has nanometer size, high surface area and loose structure. The prepared HAP had high adsorption capacity to human serum protein and the adsorption of human serum protein on the surface of HAP was confirmed by SEM. The factors which influenced the adsorption capacity such as the acidity, reaction time and the concentration of adsorbent were investigated in detail and the adsorption isothermal was also obtained. The adsorption capacity reduced while the pH value increased, and the adsorption reached equilibrium when shaking time was up to 40 min. The adsorption isotherm could be fitted by the pseudo-Langmuir type. The adsorption of human serum albumin on HAP was investigated, and the influences of adsorption on the conformation of human serum albumin were studied by infrared and ultraviolet spectroscopy. It can be seen from the FT-IR spectra that the intensity of flex vibration of C=O, N-C bonds all weakened. The calculation results of ultraviolet spectrum indicated that the quantity of α spiral structure reduced from 44% to 17.12%.

Abstract: One-dimensional ZnO nanopowder was prepared by chemistry liquid-phase method with polyethylene glycol (PEG) as additive in [Zn(OH)4]2- premonitory solution. TEM results showed that the nanopowder with the diameter of 30~50nm has the structure such as the good crystal state and well-defined crystallographic surfaces. The UV–Vis absorption revealed that the ZnO nanopowder have strong absorption in the UV region. The function of polyethylene glycol and the effects of solvent conditions were discussed.