| 1. |
- Tian, Yu-peng, et al.
(författare)
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Synthesis, crystal structure and NLO properties of a novel ruthenium(II) complex with unusual coordination mode
- 2005
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Ingår i: Transition metal chemistry (Weinheim). - : Kluwer Academic Publishers. - 0340-4285 .- 1572-901X. ; 30:7, s. 778-785
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Tidskriftsartikel (refereegranskat)abstract
- A new Schiff base 4-[N-hydroxyethyl-N-(methyl)amino]benzaldehyde S-methyl dithiocarbazate (HL, where H is a dissociable proton) and the ruthenium complex [Ru(bpy)2L]PF6 (bpy = 2,2′-bipyridine) have been synthesized. The structural determinations of the ligand and its ruthenium complex, by X-ray crystallography, show that the ligand is coordinated as a monoanionic bidentate N, S-donor, forming a four-member chelate ring with a bite angle of 65.91°. The complex shows intense MLCT transitions in the visible region. Fluorescent and electrochemical properties have been also studied. The complex in DMF solution exhibited a strong two-photon absorption (t.p.a.) at 532 nm nanosecond laser pulses. The t.p.a. coefficient β, t.p.a. cross-section σ and the third-order optical nonlinearity χ(3) of the complex and the ligand have been determined by the Z-scan technique.
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| 2. |
- Zhang, Xin, et al.
(författare)
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Tailorable Membrane-Penetrating Nanoplatform for Highly Efficient Organelle-Specific Localization
- 2021
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Ingår i: Small. - : Wiley-V C H Verlag GMBH. - 1613-6810 .- 1613-6829. ; 17:31
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Tidskriftsartikel (refereegranskat)abstract
- Given the breadth of currently arising opportunities and concerns associated with nanoparticles for biomedical imaging, various types of nanoparticles have been widely exploited, especially for cellular/subcellular level probing. However, most currently reported nanoparticles either have inefficient delivery into cells or lack specificity for intracellular destinations. The absence of well-defined nanoplatforms remains a critical challenge hindering practical nano-based bio-imaging. Herein, the authors elaborate on a tailorable membrane-penetrating nanoplatform as a carrier with encapsulated actives and decorated surfaces to tackle the above-mentioned issues. The tunable contents in such a versatile nanoplatform offer huge flexibility to reach the expected properties and functions. Aggregation-induced emission luminogen (AIEgen) is applied to achieve sought-after photophysical properties, specific targeting moieties are installed to give high affinity towards different desired organelles, and critical grafting of cell-penetrating cyclic disulfides (CPCDs) to promote cellular uptake efficiency without sacrificing the specificity. Hereafter, to validate its practicability, the tailored nano products are successfully applied to track the dynamic correlation between mitochondria and lysosomes during autophagy. The authors believe that the strategy and described materials can facilitate the development of functional nanomaterials for various life science applications.
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| 3. |
- Ding, Aixiang, et al.
(författare)
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Complex-Formation-Enhanced Fluorescence Quenching Effect for Efficient Detection of Picric Acid
- 2014
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Ingår i: Chemistry - A European Journal. - : Wiley-VCH Verlag. - 0947-6539 .- 1521-3765. ; 20:38, s. 12215-12222
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Tidskriftsartikel (refereegranskat)abstract
- Amine-functionalized alpha-cyanostilbene derivatives (Z)-2-(4-aminophenyl)-3-(4-butoxyphenyl) acrylonitrile (ABA) and (Z)-3-(4-butoxyphenyl)-2-[4-(butylamino) phenyl] acrylonitrile (BBA) were designed for specific recognition of picric acid (PA), an environmental and biological pollutant. The 1:1 host-guest complexes formed between the chemosensors and PA enhanced fluorescence quenching, thus leading to sensitive and selective detection in aqueous media and the solid phase.
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| 4. |
- Hu, Zhang-Jun, et al.
(författare)
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A TPA-caged precursor of (imino)coumarin for "turn-on" fluorogenic detection of Cu
- 2016
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Ingår i: Analytica Chimica Acta. - : ELSEVIER SCIENCE BV. - 0003-2670 .- 1873-4324. ; 933, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- We strategize to utilize the precursors of (imino) coumarin fluorophores to deliver novel reactive Cu+ probes, where tris[(2-pyridyl)-methyl] amine (TPA) works as a reactive receptor towards Cu+. To verify this strategy, CP1, a representative probe and relevant sensing behaviors towards Cu+ are presented here. CP1 features good solubility and fast response for monitoring labile copper in aqueous solution and live cells. The sensing mechanism of CP1 is determined by HPLC titration and mass spectrometric analysis. The probe CP1 exhibits a 60-fold fluorescence enhancement and a detection limitation of 10.8 nM upon the detection of Cu+. CP1 is further applied for imaging labile copper in live cells. This work provides a starting point for future development of Cu+ probes, based on in situ formation of (imino) coumarin scaffolds, as well as their further investigations of copper signaling and biological events. (C) 2016 Elsevier B.V. All rights reserved.
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| 5. |
- Rong, Yu, et al.
(författare)
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Yellow Fluorescent Semiconducting Polymer Dots with High Brightness, Small Size, and Narrow Emission for Biological Applications
- 2014
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Ingår i: ACS Macro Letters. - : American Chemical Society (ACS). - 2161-1653. ; 3:10, s. 1051-1054
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Tidskriftsartikel (refereegranskat)abstract
- Cross-linked polymer dots with intense and narrow yellow emission were designed using boron-dipyrromethene (BODIPY) polymer as the acceptor and poly[9,9-dioctylfluorenyl-2,7-diyl-co-1,4-benzo-{2,1-3}-thiadiazole] (PFBT) polymer as the donor. The emission fwhms of the polymer dots (Pdots) were 37 nm. CL-BODIPY 565 Pdots were about S times brighter than commercial quantum dots (Qdots) 565 under identical experimental conditions. Specific cellular targeting indicated that the small, bright, and narrow emissive CL-BODIPY 565 Pdots are promising probes for biological applications.
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| 6. |
- Tian, Yupeng, et al.
(författare)
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Two novel two-photon polymerization initiators with extensive application prospects
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier. - 0009-2614 .- 1873-4448. ; 388:4-6, s. 325-329
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Tidskriftsartikel (refereegranskat)abstract
- Two novel two-photon polymerization initiators, 10-ethyl-3-E-(4-(N,N′-di-n-butylamino)styryl)phenothiazine 5 and 10-ethyl-3,7-E,E-bis(4-(N,N′-di-n-butyl amino)styryl)phenothiazine 6, have been efficiently synthesized with room temperature solid phase Wittig reaction. Two initiators were found to exhibit good single-photon fluorescence emission and their quantum yields, lifetimes and solvent effects have been studied in detail. Two-photon fluorescence spectra were investigated under 800 nm fs laser pulse and two-photon absorption (TPA) cross-sections of the initiators have been evaluated by theoretical calculation.Two-photon initiating polymerization microfabrication experiments have been carried out and artificial defects were made and polymerization mechanism was also discussed.
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| 7. |
- Zhang, G., et al.
(författare)
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Schiff base modified α-cyanostilbene derivative with aggregation-induced emission enhancement characteristics for Hg2+ detection
- 2014
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 202, s. 209-216
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Tidskriftsartikel (refereegranskat)abstract
- A Schiff base functionalized α-cyanostilbene derivative (TS) has been synthesized via a simple and straightforward method and characterized by FT-IR, 1H NMR, 13C NMR and mass spectra. TS possessed excellent AIEE properties and exhibited turn-on fluorescent responses to Hg2+. The results of UV-vis and fluorescence titration experiments revealed that TS was selective and sensitive to Hg2+ in pure THF and aqueous environment. The coordination of TS and Hg2+ ions generated TS-Hg complex locked the dancing molecule because of the flexible chain in the middle of the molecule and the complex was lower soluble induced formation of large aggregates that further limited the non-radiative relaxation channel enhanced emission after adding Hg2+ ions in aqueous solution, which had been confirmed by 1H NMR and dynamic light scattering (DLS). © 2014 Published by Elsevier Inc.
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| 8. |
- Zhang, Mingliang, et al.
(författare)
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Synthesis, crystal structure and two-photon property studies on a series of complexes derived from a novel Schiff base ligand
- 2004
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Ingår i: Transition metal chemistry (Weinheim). - : Kluwer Academic Publishers. - 0340-4285 .- 1572-901X. ; 29:6, s. 596-602
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Tidskriftsartikel (refereegranskat)abstract
- A new Schiff base ligand derived from S-benzyldithiocarbazate and 4-[N-hydroxy ethyl-N-(methyl)amino]benzaldehyde (HL, where H is a dissociable proton) and its NiII, CuII, ZnII and PdII complexes were prepared and fully characterized. The structures of HL and Ni(L)2 were determined by X-ray diffraction analysis, which revealed that the geometry of the NiII ion is square-planar with two equivalent Ni=N and Ni=S bonds, and that the two neighboring molecules in two layers have weak contact. The electronic spectra and solution fluorescence of the ligand and the complexes were studied, and the quantum yields of single-photon fluorescence for the compounds were determined. The compounds possess two-photon absorption (t.p.a.) character and the t.p.a. coefficient β and t.p.a. cross-section σ were determined by the Z-scan technique. Especially, the Zn(L)2complex and the HL ligand exhibit intensive two-photon fluorescence (t.p.f.) at 800 nm laser pulses in the femtosecond regime.
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| 9. |
- Eriksson, Peter, 1989-
(författare)
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Cerium Oxide Nanoparticles and Gadolinium Integration : Synthesis, Characterization and Biomedical Applications
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A challenging task, in the area of magnetic resonance imaging is to develop contrast enhancers with built-in antioxidant properties. Oxidative stress is considered to be involved in the onset and progression of several serious conditions such as Alzheimer’s and Parkinson’s disease, and the possibility to use cerium-contained nanoparticles to modulate such inflammatory response has gained a lot of interest lately. The rare earth element gadolinium is, due to its seven unpaired f-electrons and high symmetry of the electronic state, a powerful element for contrast enhancement in magnetic resonance imaging. Chelates based on gadolinium are the most commonly used contrast agents worldwide. When introducing external contrast agents there is always a risk that it may trigger inflammatory responses, why there is an urgent need for new, tailor-made contrast agents.Small sized cerium oxide nanoparticles have electronic structures that allows coexistence of oxidation states 3+ and 4+ of cerium, which correlates to applicable redox reactions in biomedicine. Such cerium oxide nanoparticles have recently shown to exhibit antioxidant properties both in vitro and in vivo, via the mechanisms involving enzyme mimicking activity.This PhD project is a comprehensive investigation of cerium oxide nanoparticles as scaffold materials for gadolinium integration. Gadolinium is well adopted into the crystal structure of cerium oxide, enabling the combination of diagnostic and therapeutic properties into a single nanoparticle. The main focus of this thesis project is to design cerium oxide nanoparticles with gadolinium integration. A stepwise approach was employed as follows: 1) synthesis with controlled integration of gadolinium, 2) material characterization by means of composition crystal structure, size, and size distribution and 3) surface modification for stabilization. The obtained nanoparticles exhibit remarkable antioxidant capability in vitro and in vivo. They deliver strongly enhanced contrast per gadolinium in magnetic resonance imaging, compared to commercially available contrast agents.A soft shell of dextran is introduced to encapsulate the cerium oxide nanoparticles with integrated gadolinium, which protects and stabilizes the hard core and to increases their biocompatibility. The dextran-coating is clearly shown to reduce formation of a protein corona and it improves the dispersibility of the nanoparticles in cell media. Functionalization strategies are currently being studied to endow these nanoparticles with specific tags for targeting purposes. This will enable guidance of the nanoparticles to a specific tissue, for high local magnetic resonance contrast complemented with properties for on-site reduced inflammation.In conclusion, our cerium oxide nanoparticles with integrated gadolinium, exhibit combined therapeutic and diagnostic, i.e. theragnostic capabilities. This type of nanomaterial is highly promising for applications in the field of biomedical imaging.
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| 10. |
- Eriksson, Peter, et al.
(författare)
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Cerium oxide nanoparticles with antioxidant capabilities and gadolinium integration for MRI contrast enhancement
- 2018
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The chelating gadolinium-complex is routinely used as magnetic resonance imaging (MRI) -contrast enhancer. However, several safety issues have recently been reported by FDA and PRAC. There is an urgent need for the next generation of safer MRI-contrast enhancers, with improved local contrast and targeting capabilities. Cerium oxide nanoparticles (CeNPs) are designed with fractions of up to 50% gadolinium to utilize the superior MRI-contrast properties of gadolinium. CeNPs are well-tolerated in vivo and have redox properties making them suitable for biomedical applications, for example scavenging purposes on the tissue-and cellular level and during tumor treatment to reduce in vivo inflammatory processes. Our near edge X-ray absorption fine structure (NEXAFS) studies show that implementation of gadolinium changes the initial co-existence of oxidation states Ce3+ and Ce4+ of cerium, thereby affecting the scavenging properties of the nanoparticles. Based on ab initio electronic structure calculations, we describe the most prominent spectral features for the respective oxidation states. The as-prepared gadolinium-implemented CeNPs are 3-5 nm in size, have r(1)-relaxivities between 7-13 mM(-1) s(-1) and show clear antioxidative properties, all of which means they are promising theranostic agents for use in future biomedical applications.
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