A green solvent for operating highly efficient low-power photon upconversion in air

Abstract

Air-stable, highly efficient and bio-safe triplet–triplet annihilation upconversion (TTA-UC) is achieved in a terpene-based green solvent d-limonene.

Visible-to-ultraviolet (<340 nm) photon upconversion by triplet–triplet annihilation in solvents

“…2e were not considered to be governed by residual oxygen in the solvents, which was the case in previous visible-to-visible UC studies. [64][65][66][67][68] This is partly because the use of D-limonene, which scavenged residual oxygen efficiently and helped to attain stable visible-to-visible UC, 60 completely suppressed the UC emission in the present study. That the UC emission decays observed in Fig.…”

“…† We included D-limonene because it has been reported to prevent degradation of solutes in visible-to-visible UC by functioning as a strong antioxidant that quickly scavenges residual oxygen. 60 Additionally, in the former half of this study, we included the ionic liquid [C 4 dmim][NTf 2 ] as a reference solvent because it enables highly stable red-to-blue UC 16,[21][22][23] (Fig. S1, ESI †).…”

Photon Upconversion Hydrogels for 3D Optogenetics

“…Nevertheless, it is possible to both solubilize and improve the oxidative stability of TTA‐UC chromophores using reductive oils. [ 35,36 ] Therefore, we tested a variety of emulsions for upconversion stability in the presence of oxygen and for cytotoxicity by varying the oil phase of the emulsions, including both natural soybean oil and D‐limonene as antioxidant solvents [ 35,36 ] and TMB as a control organic solvent. Finally, we tested the cytotoxicity of three types of non‐ionic surfactants (Pluronic F127, Tween 80 and Triton X‐100).…”

Efficiently Enhanced Triplet–Triplet Annihilation Upconversion Boosted by Multibandgaps Photonic Crystals

“…Pd­(II)­octaethylporphyrin (PdOEP) was chosen as the sensitizer, and athracene-2-carboxylic acid (AnCOOH) was used as the triplet acceptor. d -limonene, a green solvent for operating highly efficient low-power upconversion in air, was applied as the cosolvent with ethanol (v/v% = 1:9). Their linear absorbance, single-photon-excited fluorescence, and phosphorescence were investigated.…”

“…2 Among various organic upconversion materials with different mechanisms, 3 triplet−triplet annihilation UC (TTA-UC) 4 has been actively investigated in recent years. 5 Great progress in TTA-UC property has been realized such as noncoherent low-power illumination like sunlight, 6 stable emission under air atmosphere, 7,8 and even in water, 9 which promoted the TTA-UC's applications in background-free bioimaging 10 or stimuliresponsive sensing 11,12 and other life science scenarios. 13 However, the limitation of the TTA-UC efficiency is still the key bottleneck for many practical applications.…”