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Peripheral RAFT Polymerization on a Covalent Organic Polymer with Enhanced Aqueous Compatibility for Controlled Generation of Singlet Oxygen
摘要： A covalent organic polymer (COP) is prepared by 4,4’,4’’,4’’’-(porphyrin-5,10,15,20-tetrayl)tetraaniline (TAPP) with 4,4’-(anthracene-9,10-diyl)dibenzoic acid (ADDA) via 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/4-dimethylaminopyridine coupling. The COP is further modified with a hydrophilic polymer, poly(poly(ethylene glycol) methyl ether methacrylate) by grafting-from reversible-addition-fragmentation chain transfer (RAFT) polymerization to enhance its solubility in various solvents. The modified COP can bind singlet oxygen through the formation of endoperoxide by ADDA upon the exposure to red light irradiation. Singlet oxygen can be then released via the photodynamic mechanism or the cycloreversion by endoperoxide when heated at 110 8C. These results open new possibilities for simultaneous generation of singlet oxygen by the photodynamic route and singlet oxygen carriers, demonstrating promise for treating hypoxic tumors.
关键词： endoperoxides,grafting-from,covalent organic polymers,singlet oxygen,photodynamic mechanism
更新于2025-09-23 15:21:01
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Arene Ruthenium Metalla-Assemblies with Anthracene Moieties for PDT Applications
摘要： The synthesis and characterization of three metalla-rectangles of the general formula [Ru4(η6-p-cymene)4(μ4-clip)2(μ2-Lanthr)2][CF3SO3]4 (Lanthr: 9,10-bis(3,3’-ethynylpyridyl) anthracene; clip = oxa: oxalato; dobq: 2,5-dioxido-1,4-benzoquinonato; donq: 5,8-dioxido-1, 4-naphthoquinonato) are presented. The molecular structure of the metalla-rectangle [Ru4(η6-p-cymene)4(μ4-oxa)2(μ2-Lanthr)2]4+ has been con?rmed by the single-crystal X-ray structure analysis of [Ru4(η6-p-cymene)4(μ4-oxa)2(μ2-Lanthr)2][CF3SO3]4 · 4 acetone (A2 · 4 acetone), thus showing the anthracene moieties to be available for reaction with oxygen. While the formation of the endoperoxide form of Lanthr was observed in solution upon white light irradiation, the same reaction does not occur when Lanthr is part of the metalla-assemblies.
关键词： photodynamic therapy,metalla-assemblies,singlet oxygen,arene ruthenium,anthracene
更新于2025-09-23 15:21:01
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Effect of Toxic Metal Ions on Photosensitized Singlet Oxygen Generation for Photodegradation of Polyaromatic Hydrocarbon Derivatives and Inactivation of <i>Escherichia coli</i>
摘要： Here we report an experimental study of the effect of toxic metal ions on photosensitized singlet oxygen generation for photodegradation of PAH derivatives, Anthracene-9,10-dipropionic acid disodium salt (ADPA) and 1,5-dihydroxynapthalene (DHN) and photoinactivation of E. coli bacteria by using cationic meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (TMPyP) as a singlet oxygen photosensitizer. Three s-block metals ions, such as Na+, K+, and Ca2+ and five toxic metals such as Cd2+, Cu2+, Hg2+, Zn2+, and Pb2+ were studied. The s-block metal ions showed no change of the rate of photodegradation of ADPA or DHN by TMPyP whereas a dramatic change in the photodegradation of ADPA and DHN were observed in the presence of toxic metals. The maximum photodegradation rate constants of ADPA and DHN were observed for Cd2+ ions [(3.91 ± 0.20) × 10-3 s-1 and (7.18 ± 0.35) × 10-4 s-1, respectively]. Strikingly, the photodegradation of ADPA and DHN was almost completely inhibited in the presence of Hg2+ ions and Cu2+ ions. A complete inhibition of growth of E. coli was observed upon visible irradiation of E. coli solutions with TMPyP and toxic metal ions particularly, Cd2+, Hg2+, Zn2+, and Pb2+ ions, except for Cu2+ ions where a significantly slow inhibition of E. coli’s growth was observed.
关键词： E. coli,photodegradation,toxic metal ions,photosensitized singlet oxygen generation,PAH derivatives,TMPyP,photoinactivation
更新于2025-09-23 15:21:01
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Fluorophore-Induced Plasmonic Current: Generation-Based Detection of Singlet Oxygen
摘要： In this work, we report the surface-based electrical detection of singlet oxygen using the emerging fluorophore-induced plasmonic current (PC) technique. By this method, we utilize the fluorescent “turn on” response of the well-known singlet oxygen sensor green (SOSG) singlet oxygen (1O2) fluorescent probe for the generation of fluorophore-induced PC in a silver nanoparticle film. To demonstrate the potential utility of this new technique, a photosensitizing molecule is used to generate 1O2 in a solution containing the SOSG probe. The resulting change in SOSG fluorescence quantum yield and extinction coefficient permits stronger energy transfer from the SOSG probe to a proximal silver nanoparticle island film located in the near-electric field of the probe. This yields an increase in the induced electric current flow, allowing for the detection of the 1O2 analyte. To the author’s knowledge, this represents the first detection of the reactive oxygen species 1O2 utilizing fluorophore-induced PC methodology and even broader electrical detection of 1O2. This is significant as it opens the possibility for 1O2 detection methods which do not require a traditional “photodetector” and associated optics, simplifying the instrumentation over existing fluorescence detection methods and potentially even lowering the cost.
关键词： plasmonic electricity,plasmonics,plasmonic current,fluorescence detection,reactive oxygen species,sensing,singlet oxygen sensor green,singlet oxygen
更新于2025-09-23 15:19:57
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Chlorin e6a??CdSe/ZnS Quantum Dots Nanocomposites as Efficient Singlet Oxygen Generator
摘要： A new approach to the formation of colloidal nanocomposites based on CdSe/ZnS quantum dots and monomeric form of Chlorin e6 is suggested. We demonstrate that FRET with efficiency close to theoretical prediction can be realized in the nanocomposites, and it leads to twofold enhancement of singlet oxygen generation in comparison with the same amount of free Chlorin e6.
关键词： quantum dots,Chlorin e6,FRET,nanocomposites,photosensitizers,singlet oxygen
更新于2025-09-23 15:19:57
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Peripheral RAFT polymerization on covalent organic polymer with enhanced aqueous compatibility for controlled generation of singlet oxygen
摘要： The efficient generation of singlet oxygen has attracted a great deal of interest in various fields such as medicine, synthetic chemistry and materials science. In this study, a covalent organic polymer (COP) is prepared by crosslinking the photosensitizer 4,4',4'',4'''-(porphyrin-5,10,15,20-tetrayl)tetraaniline (TAPP) with 4,4'-(anthracene-9,10-diyl)dibenzoic acid (ADDA) via the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/4-dimethylaminopyridine (DMAP) coupling method. The COP is further modified with a hydrophilic polymer i.e. poly(poly(ethylene glycol) methyl ether methacrylate) through grafting-from reversible addition–fragmentation chain transfer (RAFT) polymerization to enhance its solubility in various solvent systems. The modified COP can bind with singlet oxygen through the formation of endoperoxide by ADDA upon the exposure to the red light irradiation. The singlet oxygen incorporated in COP can be then released via the photodynamic mechanism or the cycloreversion by endoperoxide when heated at 110 ℃. Our results have opened new possibilities for simultaneous generation of singlet oxygen by the dual mechanisms, i.e. photodynamic route and singlet oxygen carrier, which demonstrates the promising potential for treating hypoxic tumors.
关键词： RAFT,red LED,photodynamic,grafting from,singlet oxygen,covalent organic polymer,endoperoxides
更新于2025-09-23 15:19:57
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Glutathione- and light-controlled generation of singlet oxygen for triggering drug release in mesoporous silica nanoparticles
摘要： A combined stimuli-responsive photosensitiser and drug release system based on mesoporous silica nanoparticles was prepared. This nanoplatform encapsulated molecules of a zinc(II) phthalocyanine substituted with a glutathione-cleavable 2,4-dinitrobenzenesulfonate quencher and doxorubicin linked via a singlet-oxygen-cleavable 9,10-dialkoxyanthracene linker. In the presence of glutathione (in mM range) and upon irradiation (λ > 610 nm), the phthalocyanine units were activated by detaching from the quenching component to emit fluorescence and generate singlet oxygen. The latter subsequently cleaved the 9,10-dialkoxyanthracene linker to trigger the release of a doxorubicin derivative. The glutathione- and light-controlled activation and drug-release processes on this nanoplatform were demonstrated in phosphate buffered saline. The activation in fluorescence emission by intracellular thiols was also shown inside HepG2 human hepatocellular carcinoma cells. Upon irradiation, the nanosystem exhibited high cytotoxicity due to the photodynamic effect of the activated phthalocyanine units, but the cytotoxic effect of the released Dox moieties was not notable probably due to their reduced cytotoxicity as a result of the pendant substituent and the low drug loading in the nanoparticles.
关键词： mesoporous silica nanoparticles,photosensitiser,photodynamic therapy,doxorubicin,drug release,glutathione,singlet oxygen
更新于2025-09-23 15:19:57
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Heavy-atom-free charge transfer photosensitizers: Tuning the efficiency of BODIPY in singlet oxygen generation via intramolecular electron donor-acceptor interaction
摘要： To test the tunability of charge transfer (CT)-based BODIPY photosensitizers in generating singlet oxygen (1D g), twelve meso-phenyl-BODIPY (donor-acceptor) type compounds have been synthesized and fully characterized, in which the phenyl moiety is modified with respective 0, 1, 2 and 3 methoxy groups to increase its electron-donating ability. The UV-Vis absorption spectra, fluorescence emission spectra, fluorescence quantum yield, fluorescence lifetime, excited triplet state formation, and singlet oxygen formation properties are measured. DFT quantum chemical computation is also carried out to explain the experiments. The occurrence of intra-molecular CT is confirmed by UV-Vis absorption, fluorescence properties and quantum chemical computation. The triplet excited state formation is evidenced by laser flash photolysis technique. The quantitative photosensitized singlet oxygen formation is demonstrated by DPBF (diphenylisobenzofuran) chemical trapping method. This type of BODIPY CT photosensitizers show good tunability in generating singlet oxygen (1D g). When the number of methoxy group on the donor is increased (so that CT is enhanced), the efficiency of singlet oxygen generation becomes higher from 0.070 to 0.30. When solvent polarity is increased (CT is also enhanced), the efficiency of singlet oxygen generation is also increased significantly. The increase in singlet oxygen generation is accompanied by the decrease in fluorescence quantum yield and fluorescence lifetime values. These facts show that a higher CT efficiency in a simple phenyl-BODIPY donor-acceptor conjugate can lead to significant higher quantum yield of singlet oxygen generation. These results are useful in designing novel CT-based heavy-atom-free photosensitizers for photodynamic therapy of tumor.
关键词： Charge transfer photosensitizer,singlet oxygen,BODIPY,photodynamic therapy
更新于2025-09-19 17:15:36
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Suppressing Effect of 2-Nitrobenzaldehyde on Singlet Oxygen Generation, Fatty Acid Photooxidation, and Dye-Sensitizer Degradation
摘要： 2-Nitrobenzaldehyde was found to efficiently block singlet oxygen generation in a series of different test samples upon exposure to UV and visible light under aerobic conditions. The effect of quenching singlet oxygen formation was monitored in the presence of 1, 4-diazabicyclo [2.2.2] octane (DABCO) acting as a well-known singlet oxygen scavenger. A comparison of different nitrobenzaldehyde isomers with other highly effective synthetic antioxidants used in the food industry such as butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ) revealed that the protection of materials from singlet oxygen decreases in the order of 2-nitrobenzaldehyde > DABCO > TBHQ > 3-nitrobenzaldehyde > BHA > 4-nitrobenzaldehyde > BHT. Upon addition of 2-nitrobenzaldehyde, the oxidation of fatty acids and the degradation of photosensitizers was found to be considerably diminished, which indicates that the presence of 2-nitrobenzaldehyde has a significant protective influence by restricting the singlet oxygen generation and photodegradation of dyes. Moreover, the compound turned out to display its highly suppressing effects on typical singlet oxygen-dependent reactions, such as fatty acid photooxidation and dye photosensitizer degradation, in a rather broad spectral region covering wavelengths from 300 nm (UV-B) to 575 nm (close to the maximum of ambient solar radiation).
关键词： photostabilization,singlet oxygen scavenger,inhibition of fatty acid photooxidation,UV photoprotection,2-nitrobenzaldehyde
更新于2025-09-19 17:15:36
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Aggregation-induced emission (AIE)-active molecules bearing singlet oxygen generation activities: the tunable singlet–triplet energy gap matters
摘要： Herein, a series of photosensitizers were constructed of a, b and c-isomers of terpyridine and the corresponding N-methylation derivatives. Benefiting from the tunable singlet–triplet energy gap and aggregation-induced emission characteristics, two-photon active photosensitizers L2b and L2c showed relatively strong intersystem crossing facilitating 1O2 generation and cell apoptosis with near-infrared excitation.
关键词： Aggregation-induced emission,singlet oxygen generation,photodynamic therapy,photosensitizers,two-photon excitation
更新于2025-09-19 17:15:36