Plasmonic Nanoparticles for Sunscreens Design

Indianapolis, IN

Using an Evolution 300 spectrophotometer and VisionPro software, three sunscreens (Blue Lizard, Artnaturals, and Safe Harbor) of varying concentrations of zinc oxide and titanium dioxide nanoparticle concentrations were scanned to find the relative absorbances of each sunscreen over a wavelength range of 190-1100 nanometers. These scans were done in order to find what wavelengths of light these sunscreens absorb strongly, and more importantly, those potentially harmful ranges for which the coverage is low. The specific spectral ranges of interest in this paper are the UVA range (340-400 nm) and the neighborhood of 600 nm. These were considered specifically for their relevance to Chronic Actinic Dermatitis, a disease which can cause subjects to form plaques, rashes, papules, and other inflammatory symptoms of the skin when exposed to UV, or in rare cases, 600 nm light. The results of the experiment showed that none of the three sunscreens tested covered the targeted ranges effectively, with all of their high absorbancy ranges lying outside of the target ranges. Thus, in this paper we investigate the different types of plasmonic nanoparticles to find a solution for effective protection of the skin from UVA and 600 nm radiation, and design more effective sunscreens to block the light in these spectral ranges.