查看更多>>摘要：The development of improved photosensitizers for photodynamic therapy(PDT)is still a current research need.In this sense,third-generation photosensitizers employ different delivery vehicles to improve tumoral cells selectivity over healthy tissues.With this purpose in mind,we synthesized and characterized toluidine blue(TBO)derivates directed towards forming a covalent conjugation with human serum albumin(HSA)as a delivery vehicle under physiologically relevant conditions.We described herein the synthesis of 3-(2-pyridyldithio)pro-pionate(PDP)and 6-maleimidocaproate(EMC)derivatives of TBO(TBOPDP and TBOEMC,respectively),their photophysical/photochemical properties and reactivity towards HSA.Hypsochromic shifts were observed in their absorption and emission bands,higher photostability and increased singlet oxygen generation compared to TBO.Moreover,these derivatives reacted with HSA at the cysteine 34 residue through disulfide exchange or thio-Michael additions.The HSA-TBOPDP and HSA-TBOEMC conjugates were analyzed by MALDI-TOF mass spectrometry,absorption/fluorescence emission spectroscopy and circular dichroism.Conjugation preserved the protein secondary structure and the photophysical properties of the photosensitizer,although the singlet oxygen generation was much lower due to the reaction with the vehicle protein.The potential of these new derivatives with covalent-conjugation to HSA for PDT are discussed.
查看更多>>摘要：Nitric oxide(NO),an important signaling molecule of the immune,vascular and nervous system was found to be present in different concentrations in biological fluids such as blood and plasma as well as in neural tissue and endothelium.A variety of competent probes may be required to detect NO and understand its complicated biochemistry,and establish the correlation of its concentrations among different biological media to its biological effect.In order to find new probes as NO sensors,four quinoline-derived ortho-diamines were synthesized and their structures and purities were confirmed by various spectroscopic methods including single-crystal X-ray diffraction.The molecules were investigated for the bimodal sensing(UV-visible and fluorescence)potential for NO.All the probes have showcased both UV-visible and fluorescent signals towards the presence of NO due to the formation of corresponding triazoles.Interestingly,the limit of detection was observed in the nanomolar range(56.1-95 nM)for the four ligands using colorimetric signals.Among the prepared molecules,N~4-(4-chlorobenzyl)quinoline-3,4-diamine exhibited superior sensing parameters viz the limit of detection(LOD),formation constant(Kf),and quenching constant(K_(SV)).An isolated triazole further confirmed the proposed mechanism of NO detection.
查看更多>>摘要：Mitochondrial dynamics and hypochlorous acid(HQC1)are involved in many physiological and pathological processes.Therefore,the development of real-time analysis tools for biological studies involving mitochondrial dynamics and HOCl is highly significant.Herein,we report a fluorescent probe,RIC,consisting of rhodamine,imidazolium salt,and coumarin,which has high selectivity and sensitivity toward HOC1.RIC has an inherently blue fluorescence signal and can be anchored in mitochondria,which enables it to reveal changes in mitochondrial dynamics.This mitochondria-anchoring characteristic also facilitates the real-time detection of HOCl in mitochondria.To our knowledge,RIC is the first probe to detect mitochondrial dynamics and HOCl in real time.The detection limit of HOCl is as low as 3.8 nM,and RIC analyzes endogenous and exogenous HOCl in live cells.The detection capacity is pH-insensitive in the physiological pH range of mitochondria,and the HOC1-sensing process is completed within seconds in cuvettes.Furthermore,we prove that the molecular design strategy provides a general synthetic method for constructing new multifunctional probes for HOCl.
查看更多>>摘要：Two couples of enantiomeric pinene-containing N^C^N and CTSTN-coordinated Pt(II)isocyanide complexes decorated with long alkyl chains have been prepared and characterized.Complexes(-)-l and(-)-2 form chiral ordered self-assemblies through Pt···Pt,π-π,and hydrophobic-hydrophobic interactions in nonpolar solvents,which is manifested by scanning electron and confocal microscope studies.Complexes(-)-l and(-)-2 display appreciable aggregation-induced emission enhancement behavior in the CH2Cl2/n-hexane system with the emission quantum yield(Φ_(em))intensified by a factor of twenty.The complexes exhibit thermo-responsive sol-to-gel transition and solvent-tuned emission colors in higher alcohols or alkane solvents.Considerable circularly polarized luminescence(CPL)signals deriving from chiroptically active ~3MMLCT transition with the g_(lum)value of 10~2 order have been found for most sols at RT.Despite minor structural variations in complexes(-)-l and(-)-2,the CPL activity of Pt(N^C^N)isocyanide complex(-)-1 is more sensitive to solvent and temperature.In contrast,the CPL activity of Pt(N^N^C)isocyanide complex(-)-2 is inert to external factors.This research provides a new design strategy for developing tunable CPL platinum(II)complex sol-gels.
查看更多>>摘要：A novel azahelicene-containing arene 4a,along with the preferential formed compound 3 have been synthesized via the Scholl reaction of the precursor 2 in the presence of triflic acid and different amount of DDQ.Their molecular structures were determined via single crystal X-ray diffraction,where compounds 4a containing two(Wu et al.,2017)[5]helicene unit and 3 containing one(Wu et al,2017)[5]helicene unit exhibit offset packing model including two isomers.The former 4a can pile up into a one-dimensional configuration and the latter 3 aggregates into a sandwich packing model.Compounds 2,3,4a emit strong blue,yellow and orange light,respectively along with the successive ring reconstruction.Compound 4a displays nonlinear optical property measured via open-aperture Z-scan method and its optical limiting performance is prior to that of the state-of-the-art material C_(60).
查看更多>>摘要：A series of six tripodal push-pull fluorophores with D-(π-A3)arrangement has been designed and synthesized.The structure of these fluorophores consists of a central electron-donating triphenylamine core and peripheral electron-withdrawing diazine units(pyridazine,pyrimidine,and pyrazine moieties),which are linked by an ethynylene π-spacer.The preparation of the fluorophores involves threefold Sonogashira cross-coupling reaction starting from the key tris(4-ethynylphenyl)amine intermediate.The structure and spatial arrangement of two fluorophores were completely confirmed by X-ray analysis.Thermal and electrochemical behavior of prepared fluorophores were investigated by differential scanning calorimetry and cyclic voltammetry.Their linear optical properties were examined by UV-Vis absorption,steady-state and time resolved fluorescent spectroscopy while 2 PA analysis was used for a study of the nonlinear optical response.Experimental data were supported by DFT calculations.Based on the experimental as well as theoretical data,structure-property relationships have been thoroughly revealed.
查看更多>>摘要：An aggregation-induced emission(AIE)-featured triphenyltin(IV)-acylhydrazone compound(SnTPA)was designed and characterized.SnTPA exhibited a pronounced fluorescence enhancement in the aggregate state with an absolute fluorescence quantum yield of 12.6% and blue-green emission.A series of experiments confirmed that the restricted intramolecular rotation(RIR)was the main mechanism of AIE for SnTPA.Owing to the suitable fluorescence,confocal laser detection revealed that SnTPA could accumulate in the lysosomes of A549 cells(lung cancer),leading to damage to lysosomal integrity and eventually inducing cell death.Flow cytometry confirmed that SnTPA could block cell cycle progression(S phase),induce the accumulation of intracellular reactive oxygen species(ROS),and realize apoptosis.In addition to displaying good anticancer activity(similar to cis-platin),SnTPA could also inhibit the migration of A549 cancer cells.Therefore,SnTPA car be used as an effective fluorescent organometallic targeted anticancer drug for further study.
查看更多>>摘要：To develop photovoltaic materials based on perylene diimide,two non-fullerene acceptors namely PCPD-F and PCPD-Cl are rationally designed and readily synthesized.By introducing the cyclopentadidiiophene unit with the strong electron-donating ability,PCPD-F and PCPD-Cl exhibit strong and bathochromic absorption compared to other perylene diimide derivatives.Meanwhile,different halogens in PCPD-F and PCPD-Cl significantly affect the physicochemical properties and device performance.With the substitution of chlorine atom,PCPD-Cl shows relatively broad absorption and strong crystallinity.However,the chlorination makes PCPD-Cl less miscible with polymer donors,leading to the unfavorable morphology with large-scale phase separation in organic solar cells.Consequently,the device based on PCPD-F achieves the best power conversion efficiency of 9.03% by blending with the polymer donor PM6,which is among the high-performance organic solar cells based on perylene diimide.This work demonstrates it is crucial to meticulously select the substituted atom and position in the design of non-fullerene acceptors.
查看更多>>摘要：Luminescent adducts of Eu(III)tris(p-diketonate)with 1,10-phenanthroline were synthesized.The effect of the p-diketone structure on thermodynamic and photophysical properties of Eu(III)complexes was characterized.Sensitization of Eu(III)ion by various p-diketones was evaluated.The synthesized compounds are shown to form isotropic vitrified structures at room temperature allowing to produce optically isotropic vitrified films with light transmittance of over 90% and efficient luminescence.These photostable films were characterized as potential luminescent temperature sensors.
查看更多>>摘要：Photosensitive fluorophores have grand value and bright prospective in diverse photo-controlled applications including super-resolution imaging and advanced patterning;however,photoactivatable and photoconvertible small fluorophores encounter great challenges in comparison to their fast-growing protein-based counterparts.Herein,we proposed a general design strategy to achieve state-depending photoactivatable and photoconvertible fluorophores based on an AIE-active molecular skeleton through introducing a dipyridinylethene unit which easily undergoes a rapid photocyclodehydrogenation reaction.It is found that introducing a photoactive dipyrinylethene unit into an AIE-active tetraarylethene molecule can effectively regulate its dominant photo-physical emission and photochemical reaction in a controllable way,and these combined compounds show predominant aggregation-induced emission properties in solid state but exhibit dominant photoactivatable and photoconvertible fluorescence behaviours in dispersed state.The photoactivatable and photoconvertible fluorescence is attributed to the rapid photo-induced cyclodehyrogenation reaction and AIE nature of the species involved in the photochemical processes.These findings outline a general design strategy to achieve photoactivatable and photoconvertible fluorescence systems by introducing a specific subunit easily undergoing rapid and efficient photocyclodehyrogenation reaction,and demonstrate exciting use of these state-dependent photosensitive fluorophores in diverse photo-controlled practical applications.
NSTL