Spatially Controlled UV Light Generation at Depth using Upconversion Micelles.

Autor: Zhou Q; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA., Wirtz BM; Department of Chemical Engineering, Stanford University, Stanford, 94305, CA, USA., Schloemer TH; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA., Burroughs MC; Department of Chemical Engineering, Stanford University, Stanford, 94305, CA, USA., Hu M; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA., Narayanan P; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA.; Department of Chemistry, Stanford University, Stanford, 94305, CA, USA., Lyu J; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA., Gallegos AO; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA., Layton C; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA., Mai DJ; Department of Chemical Engineering, Stanford University, Stanford, 94305, CA, USA., Congreve DN; Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA.
Jazyk: angličtina
Zdroj: Advanced materials (Deerfield Beach, Fla.) [Adv Mater] 2023 Nov; Vol. 35 (46), pp. e2301563. Date of Electronic Publication: 2023 Oct 15.
DOI: 10.1002/adma.202301563
Abstrakt: UV light can trigger a plethora of useful photochemical reactions for diverse applications, including photocatalysis, photopolymerization, and drug delivery. These applications typically require penetration of high-energy photons deep into materials, yet delivering these photons beyond the surface is extremely challenging due to absorption and scattering effects. Triplet-triplet annihilation upconversion (TTA-UC) shows great promise to circumvent this issue by generating high-energy photons from incident lower-energy photons. However, molecules that facilitate TTA-UC usually have poor water solubility, limiting their deployment in aqueous environments. To address this challenge, a nanoencapsulation method is leveraged to fabricate water-compatible UC micelles, enabling on-demand UV photon generation deep into materials. Two iridium-based complexes are presented for use as TTA-UC sensitizers with increased solubilities that facilitate the formation of highly emissive UV-upconverting micelles. Furthermore, this encapsulation method is shown to be generalizable to nineteen UV-emitting UC systems, accessing a range of upconverted UV emission profiles with wavelengths as low as 350 nm. As a proof-of-principle demonstration of precision photochemistry at depth, UV-emitting UC micelles are used to photolyze a fluorophore at a focal point nearly a centimeter beyond the surface, revealing opportunities for spatially controlled manipulation deep into UV-responsive materials.
(© 2023 Wiley-VCH GmbH.)
Databáze: MEDLINE
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