Photon Harvesting in Sunscreen‐Based Functional Nanoparticles

Abstract

The ultraviolet light component in the solar spectrum is known to cause several harmful effects, such as allergy, skin ageing, and skin cancer. Thus, current research attention has been paid to the design and fundamental understanding of sunscreen-based materials. One of the most abundantly used sunscreen molecules is Avobenzone (AB), which exhibits two tautomers. Here, we highlight the preparation of spherically shaped nanoparticles from the sunscreen molecule AB as well as from sunscreen-molecule-encapsulated polymer nanoparticles in aqueous media and study their fundamental photophysical properties by steady-state and time-resolved spectroscopy. Steady-state studies confirm that the AB molecule is in the keto and enol forms in tetrahydrofuran, whereas the enol form is stable in the case of both AB nanoparticles and AB-encapsulated poly(methyl methacrylate) (PMMA) nanoparticles. Thus, the keto-enol transformation of AB molecules is restricted to a nanoenvironment. An enhancement of photostability in both the nanoparticle and PMMA-encapsulated forms under UV light irradiation is observed. The efficient excited energy transfer (60 %) from AB to porphyrin molecules opens up further prospects in potential applications as light-harvesting systems.

A new insight into the photochemistry of avobenzone in gas phase and acetonitrile from ab initio calculations

“…Despite the fact that AB has practical importance as an UVA filter, complete understanding of its photophysics and photochemistry is still missing due to solvent-dependent multiple relaxation pathways. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] AB is a b-dicarbonyl compound liable to keto-enol tautomerization. Many theoretical and experimental studies provided evidence that in the ground state the chelated enol form is favored due to the intramolecular hydrogen bond.…”

Photon Harvesting in Conjugated Polymer-Based Functional Nanoparticles

“…Fluorophore-doped conjugated PNPs are established to be alternative next-generation luminescence sources due to brighter luminescence properties, easy solution-based synthetic procedures, greater photostability, and extremely nontoxic behavior. Considering the advantages of PNPs, sunscreen-based polymer nanomaterials would be a potential for healthcare applications . Emphasis has been given to the role of particle size and population of the dye molecules inside of the PNPs in rotational dynamics and particle brightness.…”

“…Considering the advantages of PNPs, sunscreen-based polymer nanomaterials would be a potential for healthcare applications. 117 Emphasis has been given to the role of particle size and population of the dye molecules inside of the PNPs in rotational dynamics and particle brightness. Time-resolved photoluminescence spectroscopic analysis on the cascade energy transfer for white light and singlet oxygen generation in multiple fluorophore-containing PNP systems is given.…”

Encapsulation of organic ultraviolet photoprotective actives into poly(methyl methacrylate) nanoparticles for sunscreen formulations

“…Mandal et al 26 investigated the photophysical properties and photostability of AVO in three different systems: a solution of tetrahydrofuran (THF) and AVO; a dispersion of AVO nanoparticles in water; and PMMA nanoparticles (loaded with AVO) dispersed in water. The authors showed that the encapsulation of AVO in PMMA by the precipitation technique restricted the keto‐enol transformation.…”