查看更多>>摘要：New temperature-and polarity-sensitive dye probes were synthesized,which demonstrate intramolecular energy transfer from excited violet pyrene chromophore to green dansyl chromophore.Fluorescence of these dye probes is highly sensitive to environment polarity changes.The intramolecular energy transfer efficiencies of these dye probes increase from 55.0% in nonpolar solvent environment to 95.3% in polar solvent environment.The emitting-light colors of these dye probes change from blue in nonpolar solvent environment to yellow in polar solvent environment.These dye probes demonstrate highly temperature-sensitive fluorescence changes due to intramolecular energy transfer ON/OFF under environment cooling/heating condition.Fluorescence intensity of these dye probes significantly changes with environment temperature.Dynamic Diels-Alder covalent bonds enable dye exchange and conversion to achieve structurally optimized emitting-lighting probes.
查看更多>>摘要：Photothermal therapy(PIT)has gained more and more attention in the field of cancer therapy owing to its outstanding efficacy.However,the overexpression of heat shock proteins(HSPs)within tumor cells upon heating can alleviate the damage of high temperature to cells,which significantly restrict the therapeutic efficiency of PTT.To achieve a better therapeutic efficacy,combining other kinds of therapeutic modalities such as chemotherapy and immunotherapy with PTT has been widely reported.However,most of these combination therapeutic systems may suffer from the issue of increased side effect.Recently,an oxygen-independent modality,thermodynamic therapy(TDT),has shown its great promise in combining with PTT for developing combination therapeutic modality.TDT utilizes carbon radicals to kill cancer cells upon heating,and is a PTT-synergized modality which can improve the efficacy of PTT without inducing additional side effect.In this review,we summarize recent advances in organic nanomaterials for photothermal/thermodynamic combination therapy of cancer.Organic nanomaterials with NIR-I or NIR-II light triggered PTT/TDT are sequentially introduced.At last,conclusion and future perspectives of this field are discussed.
查看更多>>摘要：It is urgently required to develop the molecular agents with high therapeutic efficacy and low side effects for precise cancer therapy.Herein,an advanced multifunctional prodrug B-BDP-CL-CPT,consisting of a glutathione(GSH)-responsive boron dipyrromethene(BDP)-based photosensitizer,a chemo drug camptothecin(CPT),a reactive oxygen species(ROS)-sensitive chain linking BDP with CPT,and a biotin fragment with specific affinity to biotin-receptor,was designed and synthesized.Owing to the introduction of 2,4-dinitrobenzenesulfonate(DNBS)as the quencher into BDP core and chemical modification of CPT at the active site,B-BDP-CL-CPT is non-cytotoxic.Having biotin as the targeting ligand,the prodrug can be efficiently internalized by biotin-acceptor positive cancer cells,and then activated to generate substantial light-induced ROS through removal of the stopper DNBS by intracellular GSH which is abundant in cancer cells.The resulting ROS can not only serve for photodynamic therapy(PDT)but also further cleave thioketal linkage causing the release of CPT,to achieve dual PDT and chemotherapy.And the combination of preferential accumulation with specific activation in tumor tissues for this prodrug is conducive to improving the dual therapeutic outcome meanwhile greatly reducing the photo-damage and the release of CPT in adjacent healthy tissues.In addition,the activated B-BDP-CL-CPT can give bright fluorescence signals which are favor for imaging-guided PDT and real-time tracking the release of therapeutic agent.The in vitro and in vivo investigations have been performed to demonstrate the targeted and combined anticancer activities of this prodrug against HepG2 and HeLa cancer cells,and the mice with H22 tumors.This study proposes a new tactics for highly efficient and precise cancer treatment.
查看更多>>摘要：Porphyrin derivatives present an excellent ability to act as photosensitizers(PS)in photodynamic therapy(PDT).Ruthenium and iridium complexes,mainly containing pyridine ligands,also have been highlighted as potential PS for PDT,due to their photochemical and photophysical properties.The combination of porphyrin derivatives with iridium or ruthenium ions may create singular features and,consequently,improve the PDT effect.In this paper,we report the synthesis,characterization and efficacy of porphyrin derivatives bearing attached ruthenium or iridium terpyridine units to act as PS against resistant melanoma cells(B16F10 cell model).The choice of the porphyrin derivatives to carry out this study was related with their efficacy to generate reactive oxygen species(ROS),the presence of anchoring groups to enable the coordination with ruthenium and iridium metal ions and on the studies of subcellular localization.In the PDT studies,a cell viability decrease was observed in the presence of compounds 4a(ruthenium derivative)and 3b(iridium derivative)at lower concentrations due to the high values of singlet oxygen quantum yield and cellular uptake found.The fluorescence of derivative 3b was observed uniformly dispersed by the cells.
查看更多>>摘要：New blue fluorescent dopant materials based on pyrene moieties were synthesized by variation of the positions of N-phenylnaphthalene-1-amine functional groups to minutely control the molecular geometry and photophysical properties.A blue dopant with the functional groups at the 1,6 position exhibited the highest photoluminescence quantum yield.3,8-Diisopropyl-N~1,N~6-di(naphthalen-1-yl)-N~1,N~6-diphenylpyrene-1,6-diamine(DI-1,6-DAP)exhibited the best performances with a current efficiency of up to 6.89 cd/A and external quantum efficiency of 5.45% among the new synthetic dopants prepared in this study.In terms of color purity,the case of substituting arylamine groups at the 1,7 position of the pyrene core unit[N~1,N~7-di(naphthalen-1-yl)-N~1,N~7-diphenylpyrene-1,7-diamine(1,7-DAP)] was superior to the case of attaching them at the 1,6 position of the same core unit[N~1,N~6-di(naphthalen-1-y1)-N~1,N~6-diphenylpyrene-1,6-diamine(1,6-DAP)](y<0.098).
查看更多>>摘要：The assembly of hydrogen-bonded organic frameworks(HOFs)has been proposed as robust porous materials for gas storage/separation,catalysis,molecular recognition,optical applications,enzyme encapsulation,and so on.However,efficient way to obtain well-organized HOFs still remains challenge.Herein,a novel of anionic pyrene-based HOF[BMI]2[H2TBAPy] was synthesised under ionothermal conditions.Relationship between the arrangement of photoactive 1,3,6,8-tetrakis(p-benzoic acid)pyrene molecules and photophysical properties were well studied by the combination of experiments and density functional theory.Through a facile cation-exchange process,the encapsulation of EMc-A dye cations into the HOF nanochannels could sinificantly broaden its light-harvesting region to NIR.The integrated composite can turn on photoelectric activity of the title HOF owing to strong dipole-dipole interactions and efficient energy transfer between host-guest.
查看更多>>摘要：Special recognition sites in luminescent covalent organic frameworks(LCOFs)are extremely important to improve the selectivity of detection.Herein,we report on a novel LCOF named TFBD-Py-COF with three-in-one recognition traps composed of hydrogen bonding,reversible protonation of N and O-H···N=C chelating unit.TFBD-Py-COF is synthesized via 3,3',5,5'-tetraformyl-4,4'biphenyldiol(TFBD)and 4,4',4",4'''-(pyrene-1,3,6,8-tetrayl)tetra aniline(PyTTA),which has a two-dimensional dual rhombic pore structure based on AA stacking with the pore diameters of 0.88 and 1.38 nm.The hydroxyl group of TFBD-Py-COF can form hydrogen bonds with imines and induce the trans conformation of the mesoimine,as evidenced by the single crystal structure of the model compound.TFBD-Py-COF exhibits good chemical and thermal stability with a high BET surface area of 750 m~2 g~(-1).TFBD-Py-COF shows visible fluorescent color from blue to green when dispersed in different organic solvents.TFBD-Py-COF has the fluorescence chemo-sensing ability for nitro-pesticides based on electron transfer-induced fluorescence quenching mechanism,allowing a high sensitivity and low detection limit of 4.0 × 10~(-2)ppm for p-nitroaniline.In addition,TFBD-Py-COF shows reversible acidochromic behaviors and concomitant distinct fluorescent color change due to the protonation of the imine N.Furthermore,the fluorescence of TFBD-Py-COF is selectively quenched by Fe~(3+)with a Ksv of 1.1 × 10~4 and a detection limit of 0.2 μM,owing to the coordination of Fe~(3+)with the O-H···N=C chelating unit.This study demonstrates great potential of LCOFs for multifunctional detection.
查看更多>>摘要：Four thiocyanate-free ruthenium(II)dyes,[Run(4,4-dicarboxylic acid-2,2-bipyridine)2(L1 or L2)](PF6)] and[RuII(tetraethyl[2,2'-bipyridine]-4,4/-diylbis(phosphonate))2(L1 or L2)](PF6)] with different anchoring groups,coded as Rul-Ru4,were synthesized and characterized by NMR spectroscopy and mass spectrometry,and their electrochemical and photophysical properties were investigated.Density functional theory(DFT)calculation was used to gain insight into the factors responsible for photocatalytic properties of Rul-Ru4 as effective photo-sensitizers.Relative to common ruthenium dyes,such as[Ru(bpy)s]~(2+)and N719,the absorption spectra of our dyes with triphenylamine moiety are broader with enhanced molar absorptivities(e),especially,in the region between 400 nm and 650 nm.This is attributed to the extended ^-conjugation system by inserting electron-donating triphenylamine to isoquinoline through thiophene moiety in their cyclometalating(CAN)ligands,in which strong intramolecular charge transfer(ICT)ability was induced.All the new ruthenium(II)complexes were used as photosensitizers for visible-light driven hydrogen production reactions by attaching to platinized TiO2 nanoparticles(Pt-TiO2)in the presence of sacrificial electron donor(SED)ascorbic acid(AA)in purely aqueous solution.A H2 turnover number(TON)up to 14232 was demonstrated after 236 h irradiation.Complexes with tetraethyl[2,2/-bipyridine]-4,4/-diylbis(phosphonate)anchoring groups were found to be outperform to those with classical 4,4-dicarboxylic acid-2,2-bipyridine,which may be one of the crucial steps in designing superior ruthenium(II)photosensitizers for hydrogen generation from water.
查看更多>>摘要：In this work,the combined electronic structure calculations(OM2/MRCI and MS-CASPT2//CASSCF)and Tully's fewest-switches surface hopping dynamics simulations(OM2/MRCI)have been conducted to investigate the photoinduced ring-opening,relaxation,and subsequent isomerization of spirooxazine.The OM2/MRCI and MS-CASPT2//CASSCF methods share very similar structures of S0 and S1 minima and Si/So conical intersections,and also provide comparable relative energies at the same time.The relevant reaction paths indicate that two bonded conical intersections and two unbonded ones will play very important roles in the nonadiabatic transitions.In addition,the Si state nonadiabatic dynamics simulations reveal two effective and competitive Si->>So decay pathways via the bonded and unbonded conical intersections.And the C-O bond dissociation could take place either in the Si state before hopping or in the So state after nonadiabatic transitions,which will finally generate three types of ground-state products,i.e.the closed-loop spirooxazine,a variety of merocyanine intermediates,and a small amount of hydrogen-transferred merocyanine isomers.Besides,the out-of-plane hydrogen(HOOP)oscillations could be an efficient and ultrafast inactivation channel for the excited-state relaxation processes.The currently simulated results provide important mechanistic insights into spirooxazine-based photochromic materials.
查看更多>>摘要：In this study,two difluoroboradiazaindacene(BODIPY)compounds bearing diethylaminostyryl groups were synthesized in order to establish colorimetric and fluorometric paper-based pH sensors.The structures of these novel BODIPY compounds were identified by NMR(1H,~(13)C,~(11)B,and ~(19)F),elemental analysis,MALDI-TOF,FT-IR,UV-vis and fluorescence spectroscopies as well as single-crystal X-Ray data.The DFT study was also performed to optimize of these two novel BODIPY structures.Electrochemical measurements were applied to estimate their redox potentials.Photophysical properties such as fluorescence quantum yield and lifetimes were investigated to determine the effect of acid addition in both DMSO and 1,4-dioxane solutions of the studied BODIPY derivatives.Also,pKa values of the synthesized compounds(la and lb)were determined from absorbance and fluorescence measurements by acid titration studies.The paper-based pH sensor behavior of these BODIPY derivatives was investigated and their performances were determined on the lemon juice samples as a real sample analysis.A simple,cost-effective,rapid,portable,colorimetric,and fluorometric paper-based BODIPY sensing platform was developed in this study for the detection of the variety of pH changes in lemon juice.
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