Supramolecular Confinement within Chitosan Nanocomposites Enhances Singlet Oxygen Generation

Naim, Khalid; Nair, Sreejisha T; Yadav, Pranjali; Shanavas, Asifkhan; Neelakandan, Prakash P.

doi:10.1002/cplu.201800041

Cited by 16 publications

(12 citation statements)

References 57 publications

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“…[ 9b ] Clearly, L and ReL displayed higher capability of 1 O 2 generation due to enhanced ISC ascribed to the heavy‐atom effect. Obtained singlet oxygen quantum yield for rhenium complex is quite comparable with previously reported Re(I) non‐BODIPY systems Φ Δ = 77% [ 9b ] and 81% [ 26c ] and significantly higher than reported Re‐BODIPY systems Φ Δ = 16% [ 12d ] and 18.6%. [ 12a ]…”

Section: Resultssupporting

confidence: 87%

“…The photooxidation product of DHN is juglone, which is selectively formed by the reaction of 1 O 2 with DHN and as a result a peak around ∼410 nm arises in the UV–visible absorption spectra. [ 26 ] This transformation was monitored to quantify the singlet oxygen generation with methylene blue as a reference standard. Upon irradiating a solution of L or ReL in presence of DHN, the decreased absorption at ∼297 nm indicates the consumption of DHN, and an increase in absorption band at ∼410 nm supports the juglone formation (Figures 7 and S16).…”

Section: Resultsmentioning

confidence: 99%

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Photodynamic therapy applications of Re(I)‐BODIPY functionalized nanoparticles

Tyagi

Kaur

Sahoo³

et al. 2021

Applied Organom Chemis

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Organometallic Re(I)‐BODIPY compounds have recently received attention as metal‐based photosensitizers for photodynamic therapy (PDT) applications owing to their strong absorption in the visible region. We synthesized and characterized an organometallic [ReI(L)2(CO)3Br] (ReL) complex containing a BODIPY ligand (L) and prepared nanoparticles of the ligand (NPL) as well as the complex (NPReL). The formation of nanoparticles was confirmed by dynamic light scattering (DLS), atomic force microscopy (AFM), transmission electron microscopy (TEM), and energy dispersive X‐ray (EDX) analyses. Single‐crystal structure of ReL showed octahedral environment around Re center, and the BODIPY chromophore was placed at distances of around 12 Å. Detailed photophysical properties of ReL were investigated which showed strong visible absorption at 551 nm (ε = 1.46 × 105 M−1 cm−1) owing to π‐conjugation of BODIPY with the metal center Re(I). Efficient intersystem crossing (ISC) and formation of triplet‐excited states with lifetimes of 0.80 and 0.65 μs for L and ReL, respectively, were confirmed through nanosecond‐laser flash photolysis and density functional theory (DFT) calculations. The photosensitization efficiency of ReL was observed to be ϕΔ = 0.77. In vitro biological studies of NPReL showed negligible toxicity and reactive oxygen species (ROS) generation in the dark as compared with NPL despite the good photosensitization ability of NPL. Therefore, NPReL showed coordination‐enhanced cytotoxicity under irradiation conditions and interestingly found to be nontoxic to normal NIH3T3 cell lines in comparison with L. Flow cytometry studies further indicated that the major cause of cell death by NPReL was via apoptotic pathways (54%), which authenticates its potential as a PDT agent.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Photodynamic therapy applications of Re(I)‐BODIPY functionalized nanoparticles

Tyagi

Kaur

Sahoo³

et al. 2021

Applied Organom Chemis

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“…A simple case of supramolecular confinement of the PS and a “heavy atom effect” promoter to enhance SOG efficiency was demonstrated by Naim et al [ 63 ]. As formation of the triplet state of the PS is essential for SOG, improving the S 1 → T 1 rates should increase quantum yield (Φ Δ ) of SOG.…”

Section: Supramolecular Approaches To Singlet Oxygen Generationmentioning

confidence: 99%

“…( D ) Change in DHN and juglone mixture absorbance (signal from other species subtracted) with time for monitoring SOG. Image used with permission from published work [ 63 ].…”

Section: Figurementioning

confidence: 99%

Supramolecular Control of Singlet Oxygen Generation

et al. 2021

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Singlet oxygen (1O2) is the excited state electronic isomer and a reactive form of molecular oxygen, which is most efficiently produced through the photosensitized excitation of ambient triplet oxygen. Photochemical singlet oxygen generation (SOG) has received tremendous attention historically, both for its practical application as well as for the fundamental aspects of its reactivity. Applications of singlet oxygen in medicine, wastewater treatment, microbial disinfection, and synthetic chemistry are the direct results of active past research into this reaction. Such advancements were achieved through design factors focused predominantly on the photosensitizer (PS), whose photoactivity is relegated to self-regulated structure and energetics in ground and excited states. However, the relatively new supramolecular approach of dictating molecular structure through non-bonding interactions has allowed photochemists to render otherwise inactive or less effective PSs as efficient 1O2 generators. This concise and first of its kind review aims to compile progress in SOG research achieved through supramolecular photochemistry in an effort to serve as a reference for future research in this direction. The aim of this review is to highlight the value in the supramolecular photochemistry approach to tapping the unexploited technological potential within this historic reaction.

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“…As the chemosensor 4 was observed to selectively bind to Cu(II) in the aqueous medium, we were interested to investigate if the complex [ 4 Cu(II)] could function as a photosensitizer for the generation of ROS. 1,5‐Dihydroxynaphthalene (DHN) was used as a trap to monitor the formation of singlet oxygen because the reaction of DHN with 1 O 2 is known to be fast and can be followed by UV‐Vis absorption spectroscopy ,. An aqueous solution containing DHN and [ 4 NAs Cu(II)] was exposed to light and the absorption spectrum of DHN was recorded at regular intervals.…”

Section: Resultsmentioning

confidence: 99%

Selective Metal‐Ion Detection and Activatable Photosensitization Properties of a Tetraphenylethylene‐Based Salicylideneimine

et al. 2019

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Development of chemosensors for metal ions is an active area of research. Fluorescent chemosensors capable of detecting multiple metal ions are valuable because of their potential utility in diagnostics and environmental science. We have synthesized a Schiff‐base chemosensor based on the tetraphenylethylene chromophore. It was observed that the chemosensor interacts with Cu(II) and Zn(II) in acetonitrile with high association constants of 2.33 × 1021 and 1.33 × 1021 M−4, respectively. Moreover, the interaction of these metal ions with the chemosensor resulted in visual colour and fluorescence changes. Nanoaggregates of this molecule, on the other hand, were observed to be selective towards Cu(II) in the aqueous medium. It is also noteworthy that the binding of Cu(II) activates photosensitization property of this molecule and generates singlet oxygen efficiently.

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Supramolecular Confinement within Chitosan Nanocomposites Enhances Singlet Oxygen Generation

Cited by 16 publications

References 57 publications

Photodynamic therapy applications of Re(I)‐BODIPY functionalized nanoparticles

Photodynamic therapy applications of Re(I)‐BODIPY functionalized nanoparticles

Supramolecular Control of Singlet Oxygen Generation

Selective Metal‐Ion Detection and Activatable Photosensitization Properties of a Tetraphenylethylene‐Based Salicylideneimine

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