Green synthesis of silver nanoparticles and their effect on the skin determined using IR thermography

Abstract

In this study, silver nanoparticles (AgNPs) were prepared using a green synthesis method. The optical and structural properties of these AgNPs were studied with UV-vis spectroscopy, X-ray diffraction, FE-SEM and TEM. In the UV-vis absorption spectrum, the highest peak appeared at 400 ​nm. The AgNPs produced had a nanocrystalline cubic structure with a crystallite size of (9.25–18.61) nm, according to the X-ray pattern. The FE-SEM data demonstrated that the synthesised AgNPs combine. AgNPs examined by TEM at different magnifications revealed that most particles were spherical and evenly scattered. According to the TEM histogram, the particles were highly monodispersed AgNPs with an average diameter of 45 ​nm. An infrared thermal imaging technique (IRT) was used to clarify the change in temperature when the AgNPs affected the skin. The material was placed on the skin in two ways and on the feet of rabbits. When the AgNPs were mixed with distilled water, a decrease in temperature was noticed, likely due to the role of water in cooling the skin. When the AgNPs were mixed with commercial Vaseline, a slight increase in the skin temperature was observed. The radiance related to the change of temperature in two bands (3–5 and 8–14 ​μm) was calculated. The highest value in the range 3–5 ​μm was 0.8730 ​at the maximum temperature of 32.1 ​°C while the highest value of the 8–14 ​μm band was 0.5621 ​at a maximum temperature of 37.1 ​°C. The total spectral radioactive emission is proportional to the area under the curves and shifts towards shorter wavelengths with increasing temperature. By comparing data from line profiles from different temperatures, radial heat diffusion is observed, causing energy to be transmitted to the surrounding regions from the immersed nanoparticles.