Singlet Oxygen Generation from Polyaminoglycerol by Spin-Flip-Based Electron Transfer

Abstract

Reactive oxygen species have drawn attention owing to their strong oxidation ability. In particular, the singlet oxygen ( 1 O 2 ) produced by energy transfer is the predominant species for controlling oxidation reactions efficiently. However, conventional 1 O 2 generators, which rely on enhanced energy transfer, frequently suffer from poor solubility, low stability, and low biocompatibility. Herein, we introduce a hyperbranched aliphatic polyaminoglycerol (hPAG) as a 1 O 2 generator, which relies on spin-flip-based electron transfer. The coexistence of a lone pair electron on the nitrogen atom and a hydrogen-bonding donor (the protonated form of nitrogen and hydroxyl group) affords proximity between hPAG and O 2 . Subsequent direct electron transfer after photo-irradiation induces hPAG •+ -O 2 •– formation, and the following spin-flip process generates 1 O 2 . The spin-flip-based electron transfer pathway is analyzed by a series of photophysical, electrochemical, and computational studies. The 1 O 2 generator, hPAG, is successfully employed in photodynamic therapy and as an antimicrobial reagent.

Interpenetrating dye-functionalized indium–organic frameworks for photooxidative cyanation and oxidative cyclization

“…6d), respectively, and these higher Δ E ST proved to be able to weaken the intersystem crossing (ISC) process, which suppresses the efficient 1 O 2 generation. 68 Therefore, combining ROS assay results with previous literature, 69–72 a plausible mechanism for the regulated generation and proportion of O 2 ˙ − and 1 O 2 in different interpenetrated In-MOFs with O 2 has been proposed. As shown in Fig.…”

“…In contrast, the excessive O 2 ˙ − accumulated on In-TPBD-50 tends to trigger O 2 ˙ − -to- 1 O 2 conversion via a spin-flip electron transfer process (Fig. S51†), 69,71 while the C–O 2 –C configuration depicts the generation of In-TPBD-50- 1 O 2 intermediates (Fig. 6f).…”

Triplet generation at the CdTe quantum dot/anthracene interface mediated by hot and thermalized electron exchange for enhanced production of singlet oxygen

“…The efficient TET motivated us to perform the generation of singlet oxygen ( 1 O 2 ), which is an important reactive oxygen species for photocatalysis and photodynamic therapy. [44][45][46] In the CdTe QDs-ACA complex, the formation of ACA triplets following photoexcitation can deactivate their energy to surrounding molecular oxygen ( 3 O 2 ) species, facilitating the generation of 1 O 2 . 1,3-Diphenylisobenzofuran (DPBF) is usually used as a probe for 1 O 2 , which can react with 1 O 2 through a Diels-Alder addition reaction to induce a decrease in the absorbance around 410 nm.…”

Hidden route of protein damage through confined oxygen gas

“…The fluorescence from oxidized HPF by • OH was measured with λ ex = 485 nm and λ em = 525 nm (refs. 47,79 ). Oxidation of dihydrorhodamine 123 (DHR123) by O 2 •– was measured for the assessment of O 2 •– level (DHR123 assay) 47,80 .…”