Aggregation-induced T_(1)/T_(2)contrast enhancement for magnetic resonance imaging-guided intraoperative surgery

Magnetic resonance imaging(MRI)plays an important role in precision medicine that is hampered by the lack of contrast agents with high efficiency and the ability to translate diagnostic accuracy into therapeutic intervention.Herein,we demonstrate a DNA-based MRI probe that overcomes previous single-mode enhancement and provides a mechanism of action for aggregationinduced dual-modal MRI signal enhancement.A facile method is developed to produce aggregated T_(1)/T_(2)dual-modal NaGdF_(4):Dy@PDA-DNA(PDA=polydopamine)MRI probes.When aggregated,this probe can further amplify MRI signal intensity and exhibit improved geometrical and positional stability in vivo.The performance of the NaGdF_(4):Dy@PDA-DNA MRI probe toward MRI-guided preoperative planning and visualization-guided surgery is verified using an orthotopic tumor-bearing mouse model.The result shows that the rapid metabolism of the degraded probe leads to the mitigation of long-term toxic effects.Therefore,the developed high-performance MRI probe is of great significance for enhancing MRI diagnostic accuracy into precision medical therapeutic interventions.

Metal nanoparticle-enhanced room temperature phosphorescence of diiodofluorescein on the filter paper substrate

Metal-enhanced room temperature phosphorescence of diiodofluorescein was first observed on filter paper surface.The phosphorescence intensity is 2.5-fold brighter from diiodofluorescein on silver nanoparticles-deposited filter paper as compared with an identical control sample without silver nanoparticles.Furthermore,enhanced absorption was also observed for the same system.Our findings suggest that both singlet and triplet states can couple to surface plasmons and enhance phosphorescence quantum yields at ...

Gold Nanostars-AIE Theranostic Nanodots with Enhanced Fluorescence and Photosensitization Towards Effective Image-Guided Photodynamic Therapy

Dual-functional aggregation-induced photosensitizers(AIE-PSs)with singlet oxygen generation(SOG)ability and bright fluorescence in aggregated state have received much attention in image-guided photodynamic therapy(PDT).However,designing an AIE-PS with both high SOG and intense fluorescence via molecular design is still challenging.In this work,we report a new nanohybrid consisting of gold nanostar(AuNS)and AIE-PS dots with enhanced fluorescence and photosensitization for theranostic applications.The spectral overlap between the extinction of AuNS and fluorescence emission of AIE-PS dots(665 nm)is carefully selected using five different AuNSs with distinct localized surface plasmon(LSPR)peaks.Results show that all the AuNS s can enhance the 1 O2 production of AIE-PS dots,among which the AuNS with LSPR peak at 585 nm exhibited the highest 1 O2 enhancement factor of15-fold with increased fluorescence brightness.To the best of our knowledge,this is the highest enhancement factor reported for the metalenhanced singlet oxygen generation systems.The Au585@AIE-PS nanodots were applied for simultaneous fluorescence imaging and photodynamic ablation of HeLa cancer cells with strongly enhanced PDT efficiency in vitro.This study provides a better understanding of the metal-enhanced AIE-PS nanohybrid systems,opening up new avenue towards advanced image-guided PDT with greatly improved efficacy.

Aggregation-induced phosphorescence and mechanochromic luminescence of a tetraphenylethene-based gold(Ⅰ) isocyanide complex

In this study,a new twisting gold（Ⅰ） isocyanide complex based on tetraphenylethene（TPE）,TPE-NC-Au.was designed and synthesized.It exhibits aggregation induced phosphorescence（AIP） characteristics,owing to the incorporation of Au moiety and conformation rigidification in the aggregated states.Moreover,the emission color of the crystalline solid of TPE-NC-Au changes from blue（454 nm） to green（500 nm） in response to mechanical grinding,due to the combined effects of conformation planarization,enhanced π…π stacking,as well as the emergence of aurophilic interactions in the ground amorphous state.Notably,the emission color can be restored upon solvent fuming,associating with the reconstruction of crystalline lattices.The AIP and switchable mechanochromism of TPE-NC-Au make it suitable for potential applications in bioimaging,sensing,and optoelectronic devices.

Mononuclear aggregation-induced emission (AIE)-active gold(Ⅰ)-isocyanide phosphors: Contrasting phosphorescent mechanochromisms and effect of halogen substitutions on room-temperature phosphorescence nature

Developing phosphors with long-lifetime(millisecond scale or even longer) solid state room temperature phosphorescence(RTP) feature has attracted considerable attention. However, to date, stimuli-responsive phosphors with RTP nature are still rare due to the absence of effective guidelines for the exploitation of luminophors synchronously possessing stimuli-responsive and RTP characteristics. In this work,a series of mononuclear gold(Ⅰ) complexes are reported. All these complexes exhibit various solid-state RTP properties, and phosphor 1-Cl exhibits long-lived RTP behavior. The effect of halogen atoms on the RTP nature of these complexes is investigated in detail. Furthermore, the introduction of different types of halogen atoms can effectively regulate the phosphorescent mechanochromism phenomena of these gold(Ⅰ)-containing complexes. In addition, these phosphors display typical aggregation-induced emission(AIE) effect except for phosphor 5-CCl, which lacks hydrogen-bonding interactions compared with the other four phosphors. This work will be very helpful to the development of mechanical-force-responsive AIE phosphors with lasting RTP.

1,1’-Binaphthol annulated perylene diimides: Aggregation-induced emission enhancement and chirality inversion

Aggregation-induced emission enhancement and aggregation-induced chirality inversion are two individ-ual phenomena for the enantiomerically pure organic dyes in the aggregates.Herein we reported for the first time that these two interesting phenomena could be observed simultaneously in the aggregated states of enantiomerically pure S/R-1,1?-binaphthol annulated perylene diimides,in which two perylene diimides moieties were bridged by S/R-1,1?-binaphthol(BINOL)at the bay positions.Owing to the rotat-able C2 axes between two naphthol annulated perylene diimides moieties,both of them display intrinsic behaviors of aggregation-induced emission enhancements.At the same time,due to the steric hindrances in the imide and methoxy positions,the neighboring twoπ-systems of these two unique polycyclic aro-matic imides in poor solvents are preferable to adopt a cross-stacking mode and thus form helical X-aggregates of opposite chirality(M/P)with chirality inversion characteristics in their circular dichroism and circularly polarized luminescence spectroscopic studies.

Remarkable mechanochromism and force-induced thermally activated delayed fluorescence enhancement from white-light-emitting organic luminogens with aggregation-induced emission

The development of organic materials with white-light emission and thermally activated delayed fluorescence(TADF)properties in the solid state remain a challenge.Herein,a series of white-light-emitting organic luminogens have been developed and are found to show aggregation-induced delayed fluorescence(AIDF)characteristics.The AIDF emitters present dual-emission consisted of prompt fluorescence and TADF in the crystalline state.Their white-light emissions can be easily tuned by altering the chemical structure and connecting position of the heterocyclic aromatic substituent.Under the stimuli of mechanical force and solvent vapor,the compounds exhibit remarkable and reversible mechanochromism,in which their emission colors are switchable between white and yellow.Upon grinding,they also display linearly tunable luminescence colors,as well as force-induced TADF enhancement,which may be associated with the more compact molecular packing and the restriction of intramolecular motions.The results from time-resolved emission scanning and theoretical calculation suggest that the dual-emission of the AIDF luminogens likely results from the twisted intramolecular charge transfer transitions of the molecules,and the reversible mechanochromism properties probably stem from the interconversion of the quasi-axial and the quasi-equatorial conformations.

两种离子型铱配合物的合成、光物理性质及对OH^(-)的检测

以两种2,2’-联吡啶衍生物为中性配体,2-(3-氟苯基)吡啶为环金属配体,合成了两种新型的离子型Ir(Ⅲ)配合物Ir1和Ir2。利用核磁、质谱和晶体结构分析确认了配合物Ir1和Ir2的结构。配合物Ir1和Ir2在CH_(2)Cl_(2)溶液中的最大发射波长分别为570和528 nm,为橙红光和黄光。两种配合物在无氧CH_(2)Cl_(2)溶液中的量子产率分别为0.88和0.57,磷光寿命分别为2.43和2.40μs。通过理论计算详细讨论了中性配体的取代基种类对其光谱性质的影响。在配合物Ir1的DMSO/H_(2)O溶液中加入OH^(-)后,其发射峰强度提高了近100倍,溶液的发光颜色由红色变为明亮的绿色,检出限为8.47×10^(-6)mol/L。机理研究表明,OH^(-)取代了Ir1的中性配体上的溴取代基,形成了新的含有羟基的配合物,从而改变了Ir1的光谱特性,实现对OH^(-)的高选择性和高灵敏度检测。

不良溶剂和温度对[(TPE_(2)-BPY)_(2)-Ag]BF_(4)配合物的发光增强作用

通过引入柔性的TPE和刚性的联吡啶作为骨架,本研究设计合成L1配体,进而与AgBF4反应并在二氯甲烷/正己烷体系中扩散得到化合物[(TPE_(2)-BPY)_(2)-Ag]BF_(4)的晶体.通过电喷雾质谱、单晶数据分析确定了化合物的配位形式;通过紫外-可见吸收光谱、激发发射光谱以及寿命研究了其光学性质;更近一步地研究其对不良溶剂和温度(298 K,77 K)依赖的光物理行为.结果表明,[(TPE_(2)-BPY)_(2)-Ag]BF_(4)是一种AIPE活性配合物,通过3ILCT利用TPE2-BPY的AIE活性,增加不良溶剂的含量或降低测试温度会诱导荧光增强,且该化合物的荧光发射强度在不良溶剂正己烷含量为95%时达到最大.

A systematic study on efficiency enhancements in phosphorescent green, red and blue microcavity organic light emitting devices

A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found that the luminance output is determined by the reflectivity of the semitransparent electrode and the photopic response of the green,red and blue emitters.While the luminance enhancements of blue and red phosphorescent microcavity devices are small,a current efficiency as high as 224 cd A21 is obtained in the green phosphorescent microcavity OLEDs.

Bone analysis using an aggregation-induced emission-active iridium complex

Fluorescent analysis of bone provides valuable insights into bone structures.However,conventional dyes suffer from low specificity on bone tissue,small stokes shift,short fluorescent lifetime,and aggregation-caused quenching effect,which result in low efficacy and artifacts.In this work,we design an aggregation-induced emission(AIE)-active iridium(III)complex(Ir-BP2)as a highly selective,convenient,nondestructiveness,and dual-mode staining agent for bone analysis.Ir-BP2 containing phosphonate groups selectively binds to hydroxyapatites,the main component of bone matrix,and exhibits turn-on AIE phosphorescence with prolonged lifetime.Ir-BP2 exhibits promising biosafety and offers higher accuracy in staining calcium deposits than conventional Alizarin Red S staining assay when it is employed in real-time monitoring of osteogenesis differentiation process.A ready-to-use staining spray of Ir-BP2 is fabricated.By using fluorescent imaging and lifetime imaging,Ir-BP2 staining provides valuable insights into bone microstructure analysis,microdamage diagnosis,and bone growth state identification.Further,Ir-BP2 is successfully applied on a human spine vertebra for diagnosing bone invasiveness of eosinophilic granuloma,validating its clinical practice.This work presents a powerful tool in bone analysis and will lead to new approaches for the diagnosis and treatment of bone-related diseases.

Multifunctional AIE Molecules Possessing Long-lasting Room Temperature Phosphorescence, Thermally Activated Delayed Fluorescence and Dual-mode Mechanochromism

Two simple donor-acceptor multifunctional pure organic light-emitting molecules[(9H-carbazol-9-yl)(4-hydroxyphenyl)-methanone(CzMP)and(4-hydroxyphenyl)(10H-phenothiazin-10-yl)methanone(PTZMP)]with distinct aggregation-induced emission(AIE)properties were synthesized.Surprisingly,CzMP showed a long room temperature phosphorescence lifetime(>900 ms),and PTZMP exhibited triple emission of prompt fluorescence(PF),room temperature phosphorescence(RTP)and thermally activated delayed fluorescence(TADF).Furthermore,CzMP effectively responded to mechanical external forces and solvent fumigation,exhibiting dual-mode mechanochromic luminescence(MCL)including multiple fluorescence color shifts and phosphorescence switching.Time-dependent density functional theory(TDDFT)calculations were investigated to explain different luminescence properties of the two molecules,and the single crystal of CzMP was obtained and analyzed to demonstrate the unique molecular stacking pattern and strong intermolecular interactions in close association with phosphorescence emission.The multifunctional luminescent properties of the emitters explored in this work could be more effectively applied to a wide range of applications,such as information encryption and anti-counterfeiting.

Enhanced population of excited single state strategy:Irradiation and ultrasound dual-response and host tumor-driven nanosensitizers construction in triple synergistic therapy

Phototheranostics is an emerging field in synergistic antitumor therapy in which irradiation and sensitizers are combined to produce reactive oxygen species(ROS),bio-images,and high temperatures.All of these are arrived from the energy of sensitizers,which located in excited single state(S_(1)).Undeniably,the decentralization of the S_(1)population indirectly decreases the effect of each individual treatment.In this study,a strategy was proposed for enhancing the S_(1)population,and a sensitizer with mitochondrial targeting property,1,4-indolyl iodinated pyrrolo[3,2-b]pyrrole derivative(2I-TPIS),was assembled into adenosine triphosphate(ATP)-responsive nanoparticles(DPA-2I NPs)to achieve dual responses to irradiation and ultrasonication(US)for application to photo-sonodynamic therapy(PSDT).Compared with monotherapies,2I-TPIS generated more ROS in PSDT,inducing mitochondrial autophagy and apoptosis,which in turn triggered immunogenic cell death(ICD).Subsequently,DPA-2I NPs were constructed and self-assembled with the chemotherapeutic agents DPA-Cd and 2I-TPIS to achieve a triple synergistic strategy involving chemotherapy(CT)and PSDT.DPA-2I NPs exhibited absolute sensitization,intra-tumoral overexpression of ATP,and disassembly.Importantly,the biosafety and potent antitumor efficiency of the DPA-2I NP-based“PSDT+CT”therapy were revealed using a 4T1 tumor model.The study results provide insights into the design of sensitizers possessing a sufficient S_(1)population and a highly efficient tumor ablation capacity derived from molecular structural modulation,further enabling triple synergistic antitumor therapies,and expanding the clinical application of sensitizers.

Aggregation-enhanced direct S_(0)-T_(n) transitions and room-temperature phosphorescence in gold(I)-complex single crystals

The design of efficient aggregation-induced emission materials requires an improved understanding of photophysical processes in aggregated materials.Herein,the photophysical behavior of an Au(I)complex(R6)that exhibits intense roomtemperature phosphorescence(RTP)in crystals is described.In addition,the photophysical processes related to RTP are discussed based on the structure of the molecular aggregates and the primary structure of the molecule.An extremely efficient S_(0)-T_(n) direct transition is found to occur in the R6 crystal.Furthermore,intermolecular Au-Au interactions and the internal/external heavy-atom effects of Au atoms are demonstrated to enhance the electronic transitions involving intersystem crossing,namely,direct S_(0)-T_(n) excitation,radiative T_(1)-S_(0) transition(phosphorescence),and S_(1)-T_(n) intersystem crossing.Because of the dense molecular packing,both Au-Au interactions and heavy-atom effects play important roles in the crystals.As a result,R6 shows more efficient RTP in crystals than in solution.These insights into the mechanism of highly efficient RTP in Au(I)-complex crystals are expected to advance the development of new luminogens for a variety of sensing and imaging applications.

Red-emitting tetraphenylethylene derivative with aggregation-induced enhanced emission for luminescent solar concentrators:A combined experimental and density functional theory study

This study examines the use of an aggregation-induced enhanced emission fluorophore(TPE-MRh)to prepare red-emitting luminescent solar concentrators(LSCs)based on poly(methyl methacrylate)(PMMA)and poly(cyclohexyl methacrylate)(PCMA).TPE-MRh is a tetraphenylethylene(TPE)derivative bearing two dimethylamino push groups and a 3-methyl-rhodanine pull moiety,with absorption maxima at around 500 nm and fluorescence peak at 700 nm that strongly increases in solid-state.TPE-MRh displays a typical crystallizationinduced enhanced emission that has been rationalized by modeling the compound behavior in solution and solid-state via density functional theory calculations with the inclusion of the environment.TPE-MRh dispersed into 5×5 cm2 polymer films with a thickness of 25±5μm has revealed a partial fluorescence quenching with fluorophore content.Quantum yields(QYs)below 10%for the 2 wt.%of doping have been addressed to the formation of less emissive micro-sized clusters of fluorophores.PMMA slabs with the same surface size but 3 mm of thickness and 200 ppm of TPE-MRh have provided QY of 36.5%thanks to the attenuation of the detrimental effects of fluorophore aggregation.This feature is reflected in the LSCs performance,with devices achieving the largest power collected by the photovoltaic cell.

CaCl_2作为异硫氰酸曙红固体基质室温磷光增强剂及其在免疫分析中的应用

Room temperature phosphorescence(RTP) signal intensity of eosin-ITC on a polyamide membrane(PM) was very low, but the signal was increased obviously once some inorganic salts were added into the system at λ ex/λ em=532 nm/685 nm. The enhancement effect of ⅡA element ions(such as Ca 2+, Sr 2+ and Ba 2+) on RTP of eosin-ITC is much obvious than that of Pb 2+ and Hg 2+ used constantly as an outer heavy atom perturber in phosphorimetry. Based on that, a new solid substrate room temperature phosphorescence immunoassay(SS-RTP-IA) for the determination of the human IgG was proposed to demonstrate the feasibility using eosin-ITC as phosphorescent marker. It was found that a good linear relationship with the ΔI P was obtained when the amount of human IgG in the range from 6.25 to 400 pg/spot(corresponding to the mass concentration: 15.63 ng/mL—1 μg/L, sample volume of 0.4 μL/spot). The regression {equation} of working curve can be expressed as ΔI p=3.062+0.00864x(pg)(n=7, r=0.996), The detection limit calculated as 3S b/k is 0.394 pg/spot. The method was applied directly to the determination of IgG in human serum with a satisfying result. These results show that eosin-ITC can be used conveniently as a RTP marker of high sensitivity.

基于锰掺杂硫化锌量子点磷光信号增强快速标定多粘菌素B的研究

多粘菌素B(PMB)是一种广泛用于治疗由革兰阴性细菌引发疾病的药物,为了便于医学使用过程对多粘菌素B剂量的快速标定,本研究以锰掺杂硫化锌量子点为发光材料,基于多粘菌素B可通过静电聚集诱导增强锰掺杂硫化锌量子点室温磷光信号的机制,建立了一种可快速检测与标定药剂中多粘菌素B的方法.在优化的检测条件下,锰掺杂硫化锌量子点磷光信号变化比率(P/P_(0))与多粘菌素B浓度之间具有良好的线性响应关系,线性范围为0.1μg·mL^(-1)~8.0μg·mL^(-1),检出限为0.03μg·mL^(-1),所建立的方法具有良好的选择性及灵敏性,可用于医药制剂中多粘菌素B的快速检测与含量标定.

银二氧化硅核壳增强异硫氰酸荧光素酯滤纸基质室温磷光法检测赖氨酸

银二氧化硅核壳(Ag@SiO2)可使异硫氰酸荧光素酯(FITC)产生金属增强室温磷光(MERTP)。当所研究体系加入赖氨酸时,其MERTP猝灭。据此,建立了检测赖氨酸的新方法。在FITC和Ag@SiO2的加入量之比为1∶1.5,pH=8.0时,本方法检测赖氨酸的检出限为0.270μmol/L;线性范围为1.50～90.5μmol/L,人工合成样品加标回收率为97.0%～108.0%;相对标准偏差为2.1%(n=9)。本方法用于检测赖氨葡锌颗粒和赖氨酸磷酸氢钙片中的赖氨酸,结果满意。

Aggregation-induced emission systems involving supramolecular assembly

Aggregation-induced emission(AIE),as an exciting photophysical phenomenon,has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades.Since controllable molecular ensembles with particular morphologies and tunable functions can be elegantly constructed in the realm of supramolecular chemistry,the integration of supramolecular assembly and AIE systems can expectedly bring about luminescent materials with tunable emission and tailorable well-ordered architectures.In this review,we will provide a summary of the creation and working mechanisms of AIE systems involving supramolecular systems that are driven by different supramolecular driving forces including hydrogen bonding,host−guest interactions,metal coordination,and π-π interactions.The morphological and photoluminescent features of these AIE-active supramolecular assemblies will be elucidated,and the regulated fluorescence properties of the AIEgens induced by the assembling-disassembling processes will be discussed in detail.

Organic dye assemblies with aggregation-induced photophysical changes and their bio-applications

Phototheranostics provide a safe,effective,and noninvasive way for the diagnosis and treatment of contemporary diseases,and organic dyes play a vital role.For example,chemical modification endowed dyes with powerful reactive oxygen species or heat generation ability,favoring for photodynamic therapy and photoacoustic(PA)imaging guided photothermal therapy(PTT)of serious diseases.Therefore,photophysical properties manipulation of dyes has become the focus in current dye chemistry research.The development of aggregate science has made great effort to solve this problem.In recent years,a large number of studies have focused on molecular aggregation behavior and its effect on photophysical performance.The most famous example is the discovery of aggregation-induced emission(AIE)phenomenon.Based on AIE theory,more theories for revealing the relationship between molecular aggregation behavior and photophysical properties were proposed and elucidated.The photophysical property changes caused by dye aggregation have become a unique discipline,guiding the development of molecular science and material science.With the help of molecular self-assembly,controllable aggregation of dyes can be realized,and stable nano-theranostic reagents can be obtained.Furthermore,constructing dye assemblies with various photophysical properties will greatly reduce the cost of theranostic reagents,thus,expanding biomedical applications of organic dyes.Therefore,this review focuses on the photophysical characteristic changes caused by dye aggregation and their biological applications including,fluorescence/phosphorescence/PA imaging as well as photodynamic and PTT.This review will provide guidance for the design of organic dyes,the development of controllable aggregation methods,and the construction of multifunctional phototheranostic reagents.