5 research outputs found
Fabrication of Surface-Enhanced Raman Spectroscopy Substrates Using Silver Nanoparticles Produced by Laser Ablation in Liquids
This research describes the use surface-enhanced Raman spectroscopy (SERS)
substrates based on colloidal silver nanoparticles (AgNPs) produced by laser
ablation of silver granules in pure water that are inexpensive, easy to make,
and chemically stable. Here, the effects of the laser power, pulse repetition
frequency, and ablation duration on the Surface Plasmon Resonance peak of AgNPs
solutions, which was centered at 404 nm, were used to determine the optimal
parameters. The substrates were characterized using Raman spectroscopy, and it
was discovered that they were chemically stable within the first eight days of
storage at room temperature since the spectroscopic profiles remained constant.
The main bands were centered at 196, 640, 824, 1060, and 1538 cm-1, and they
were attributed to the vibrations of O=Ag2/Ag-N, C-S-C, C-H, C-CO, C-N, and
C=O, respectively. Additionally, these substrates had no impact on the Raman
spectrum profiles of samples of rat blood when mixed with them. In comparison
to thick blood smears on a clean piece of aluminum foil, the Raman spectral
profiles of blood samples mixed with colloidal AgNPs were 14.95 times more
enhanced. The Raman peaks noted were attributed to C-C stretching of lipids
(932 cm-1), C-N stretching (1064 cm-1), C-C stretching (1190 cm-1), CH2 wagging
(1338 and 1410 cm-1), carbonyl stretch for proteins (1650 cm-1), and C-H band
of proteins (2122 cm-1). The results on the utilization of inexpensive,
simple-to-prepare Raman substrates have the possibility of making
surface-enhanced Raman spectroscopy available to laboratories with scarce
resources in developing nations
Development and characterization of sodium alginate based active edible films incorporated with essential oils of some medicinal plants
PubMed ID: 31843601The aim of this study was to develop sodium alginate based active films incorporated with essential oils (EO) of R. officinalis L, A. herba alba Asso, O. basilicum L and M. pulegium L. the films were characterized in terms of bioactive properties including thickness, moisture content, water vapor and oxygen permeability, release test, mechanical, molecular, biodegradability and thermal properties. The results showed that the active films had a strong antibacterial effect against the six pathogenic bacteria with the inhibition zone between18.5 and 38.67 mm. furthermore, the antioxidant capacity of the films ranged from 4.57% to 23.09%. According to results of release test, physical, molecular, mechanical, biodegradability, thermal and barrier properties, the EOs were uniformly dispersed in the polymer matrix and improved slightly thermal (Tm) and barrier properties, while decreased tensile strength and it was obtained that this film is biodegradable in the soil. In conclusion, it could be said that sodium alginate based edible films incorporated with EO have a potential to be used food packaging applications. © 2019 Elsevier B.V