Hydroxyanthraquinones as sensitizers of singlet oxygen reactions: quantum yields of triplet formation and singlet oxygen generation in acetonitrile

Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen (1O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce 1O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of 1O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility.

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“…2f (refs 38, 39). This result agrees very well with that obtained using the chemical trapping method above.…”

Section: Resultsmentioning

confidence: 99%

A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation

et al. 2014

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“…Photosensitization of AQs may occur through an electron transfer (type I) or energy transfer (type II) mechanism [30,31]. One of the most important ROS, singlet oxygen ( 1 O 2 ) can be produced through the direct energy transfer between the lowest triplet (T 1 ) state AQs and the ground state oxygen ( 3 O 2 ) (Eq.…”

Section: Theoretical Prediction Of Ros Production Pathways Of Aqsmentioning

confidence: 99%

Experimental and theoretical studies on the photoinduced acute toxicity of a series of anthraquinone derivatives towards the water flea (Daphnia magna)

Wang

Chen

et al. 2009

Dyes and Pigments

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“…The photochemistry of 1,4‐benzoquinone and derivatives have been investigated intensively over the years (2–8). Most frequently, the photoprocesses of 9,10‐anthraquinone (AQ, Q in the schemes) (8–19) and the 1‐ and 2‐sulfonated or 1,5‐ and 2,6‐disulfonated derivatives, AQS1, AQS2, AQS3 and AQS4, respectively, have been studied by various methods (20–32). Photoinduced electron transfer from a suitable donor to the triplet state of AQ involves the semiquinone radical · QH/Q ·− , and the main photoproduct is 9,10‐dihydroxyanthracene (hydroquinone: QH 2 ).…”

Section: Introductionmentioning

confidence: 99%

Photoreduction of 9,10-Anthraquinone Derivatives: Transient Spectroscopy and Effects of Alcohols and Amines on Reactivity in Solution¶

Görner

2007

Photochemistry and Photobiology

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The photoreduction of 9,10‐anthraquinone (AQ), the 2‐methyl, 2‐ethyl, 2,3‐dimethyl, 1,4‐difluoro, 1‐chloro and 1,8‐dichloro derivatives as well as 1,4,4a,9a‐tetrahydroanthraquinone, 1,2‐benzanthraquinone and 6,13‐pentacenequinone in nonaqueous solution at room temperature was studied by time‐resolved UV–visible spectroscopy. Upon 308 nm excitation of AQ the triplet state reacts with alcohols and triethylamine (TEA). The rate constant of triplet quenching by amines is close to the diffusion‐controlled limit. The semiquinone radical ·QH/Q·− is the main intermediate, and the half‐life of the second‐order decay kinetics depends significantly on the donor and the medium. Photoinduced charge separation after electron transfer from amines to the triplet state of AQ in acetonitrile and the subsequent charge recombination or neutralization also were measured by transient conductivity. The maximum quantum yield, λirr= 254 nm, of photoconversion into the strongly fluorescing 9,10‐dihydroxyanthracenes is close to unity. The fluorescence with maximum at 460–480 nm and a lifetime of 20–30 ns disappears as a result of a complete recovery into AQ, when the dihydroxyanthracenes are exposed to oxygen. The mechanisms of photoreduction of parent AQ in acetonitrile by 2‐propanol and in benzene and acetonitrile by TEA are discussed. The effects of AQ follow essentially the same pattern. The various functions of oxygen, e.g. (1) quenching of the triplet state; (2) quenching of the semiquinone radical, thereby forming HO2·/O2·− radicals; and (3) trapping of the dihydroxyanthracenes are outlined.

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Hydroxyanthraquinones as sensitizers of singlet oxygen reactions: quantum yields of triplet formation and singlet oxygen generation in acetonitrile

Cited by 78 publications

References 48 publications

A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation

A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation

Experimental and theoretical studies on the photoinduced acute toxicity of a series of anthraquinone derivatives towards the water flea (Daphnia magna)

Photoreduction of 9,10-Anthraquinone Derivatives: Transient Spectroscopy and Effects of Alcohols and Amines on Reactivity in Solution¶

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