Recent Advances of Pure Organic Room Temperature Phosphorescence Materials for Bioimaging Applications

Bioimaging,as a powerful and helpful tool,which allows people to investigate deeply within living organisms,has contributed a lot for both clinical theranostics and scientific research.Pure organic room temperature phosphorescence(RTP)materials with the unique features of ultralong luminescence lifetime and large Stokes shift,can efficiently avoid biological autofluorescence and scattered light through a time-resolved imaging modality,and thus are attracting increasing attention.This review classifies pure organic RTP materials into three categories,including small molecule RTP materials,polymer RTP materials and supramolecular RTP materials,and summarizes the recent advances of pure organic RTP materials for bioimaging applications.     

金属钯/铂卟啉室温燐光探针在生物医学领域的应用研究

钯 铂 卟啉络合物在室温下发射长寿命 (ms)、长波长的光 ,这些特点使其在生物分析方面成为有用的探针。本文综述了该探针在光免疫标记、肿瘤诊断、DNA测定、生物传感器及其它方面的研究进展。引用文献 4 3篇     

Stimuli-Responsive Purely Organic Room-Temperature Phosphorescence Materials

This Minireview summarizes the recent progress of stimuli-responsive purely organic phosphorescence materials. Organic phosphorescence is closely related to the intermolecular interactions, because such interactions are beneficial to promote spin orbital coupling (SOC) and boost intersystem cross (ISC) efficiency and finally are conducive to satisfactory phosphorescence. It is found that the intermolecular interactions, which are essential for organic phosphorescence, are easily disturbed by external stimuli such as mechanical force, photon, acid, chemical vapor, leading to the luminescence change. According to this principle, various purely organic phosphorescence materials sensitive to external stimuli have been developed. This Minireview categorizes reported stimuli-responsive purely organic phosphorescence materials on the basis of different stimuli, including mechanochromism, mechanoluminescence, photoactivity, acid-responsiveness and other stimuli. Some prospective strategies for constructing stimuli-responsive purely organic phosphorescence molecules are provided.     

H-Bonding Room Temperature Phosphorescence Materials via Facile Preparation for Water-Stimulated Photoluminescent Ink

Pure organic room-temperature phosphorescence (RTP) materials built upon noncovalent interactions have attracted much attention because of their high efficiency, long lifetime, and stimulus-responsive behavior. However, there are limited reports of noncovalent RTP materials because of the lack of specific design principles and clear mechanisms. Here, we report on a noncovalent material prepared via facile grinding that can emit fluorescence and RTP emission differing from their components’ photoluminescent behavior. Exciplex can be formed during the preparation process to act as the minimum emission unit. We found that H-bonds in the RTP system provide restriction to nonradiative transition but also enhance energy transformation and energy level degeneracy in the system. Moreover, water-stimulated photoluminescent ink is produced from the materials to achieve double-encryption application with good resolution.     

Stimuli‐Responsive Circularly Polarized Organic Ultralong Room Temperature Phosphorescence

Purely organic materials showing room temperature phosphorescence (RTP) and ultralong RTP (OURTP) have recently attracted much attention. However, it is challenging to integrate circularly polarized luminescence (CPL) into RTP/OURTP. Here, we show a strategy to realize CPL‐active OURTP (CP‐OURTP) by binding an achiral phosphor group directly to the chiral center of an ester chain. Engineering of this flexible chiral chain enables efficient chirality transfer to carbazole aggregates, resulting in strong CP‐OURTP with a lifetime of over 0.6 s and dissymmetry factor of 2.3×10^?3 after the conformation regulation upon photo‐activation. The realized CP‐OURTP is thus stable at room temperature but can be deactivated quickly at 50 °C to CP‐RTP with high CPL stability during the photo‐activation/thermal‐deactivation cycles. Based on this extraordinary photo/thermal‐responsive and highly reversible CP‐OURTP/RTP, a CPL‐featured lifetime‐encrypted combinational logic device has been successfully established.     

新型二维材料MXene在生物医学的应用

MXene是一类新型的二维过渡金属碳化物和氮化物的总称,通式为M_{n + 1}X_nT_x(n = 1~3),其中M为前过渡金属元素,X为碳或氮元素,T指键合在该材料表面的氟基、羟基或氧基等活性官能团。该类材料具有超薄的结构和出色的物理化学(电子、光学、磁性等)特性,从而吸引了各领域研究人员的广泛兴趣。目前,MXene在生物医学领域的应用逐渐拓展。这主要是由于其大的表面积和在近红外区域的强吸收,加之其可以通过容易的表面修饰与多种分子或者纳米颗粒结合。在这篇综述中,我们总结了MXene在生物医学应用中的最新进展。文章首先介绍MXene的相关制备方法和表面改性手段;之后重点围绕其独特的理化性质,依次介绍该材料在抗菌材料、生物成像、肿瘤诊断治疗和生物传感等生物医学领域中的应用进展;文章最后总结讨论了MXene在生物医学应用方面面临的挑战和新机遇。预期超薄MXene及精巧设计的纳米复合物将成为多种生物医学应用的最有吸引力的生物相容性无机纳米平台之一。     

Aggregation-Induced Emission: Recent Advances in Materials and Biomedical Applications

The concept of aggregation-induced emission (AIE) has opened new opportunities in many research fields. Motivated by the unique feature of AIE fluorogens (AIEgens), during the past decade, many AIE molecular probes and AIE nanoparticle (NP) probes have been developed for sensing, imaging and theranostic applications with excellent performance outperforming conventional fluorescent probes. This Review summarizes the latest advancement of AIE molecular probes and AIE NP probes and their emerging biomedical applications. Special focus is to reveal how the AIE probes are evolved with the development of new multifunctional AIEgens, and how new strategies have been developed to overcome the limitations of traditional AIE probes for more translational applications via fluorescence imaging, photoacoustic imaging and image-guided photodynamic/photothermal therapy. The outlook discusses the challenges and future opportunities for AIEgens to advance the biomedical field.     

低温燐光的研究及应用

本文综述了44篇文献,介绍低温燐光的发展概况及其应用。     

蓝色磷光有机发光材料

有机发光二极管在信息显示和固体照明领域具有广阔的应用前景,二十多年来得到了广泛关注,取得了很大进展。但显示和照明必需的蓝色发光材料,特别是蓝色磷光材料是目前有机发光材料研究领域的瓶颈,其稳定性和效率亟待提高。本文总结了近年来蓝色磷光有机发光材料的研究进展,系统介绍了蓝色磷光染料和主体材料这两大类材料的分子设计思想和发展动态,以及它们在有机发光二极管中的应用,并对蓝色磷光有机发光材料未来的研究方向进行了展望。     

Aggregation‐Induced Emission: Recent Advances in Materials and Biomedical Applications

The concept of aggregation‐induced emission (AIE) has opened new opportunities in many research fields. Motivated by the unique feature of AIE fluorogens (AIEgens), during the past decade, many AIE molecular probes and AIE nanoparticle (NP) probes have been developed for sensing, imaging and theranostic applications with excellent performance outperforming conventional fluorescent probes. This Review summarizes the latest advancement of AIE molecular probes and AIE NP probes and their emerging biomedical applications. Special focus is to reveal how the AIE probes are evolved with the development of new multifunctional AIEgens, and how new strategies have been developed to overcome the limitations of traditional AIE probes for more translational applications via fluorescence imaging, photoacoustic imaging and image‐guided photodynamic/photothermal therapy. The outlook discusses the challenges and future opportunities for AIEgens to advance the biomedical field.     

Crystal Engineering of Room Temperature Phosphorescence in Organic Solids

We report a series of highly emissive azatriangulenetrione (TANGO) solids in which the luminescent properties are controlled by engineering the molecular packing by adjusting the steric size of substituents. The co‐alignment of “phosphorogenic” carbonyl groups within the π‐stacks results in an almost pure triplet emission in HTANGO, TCTANGO, TBTANGO and TITANGO, while their rotation by ≈60° in the sterically hindered tBuTANGO leads to an almost pure singlet emission. Despite strong π‐interactions, aggregation‐induced quenching and triplet–triplet annihilation are avoided in HTANGO and TCTANGO which display efficient phosphorescence in the solid state. To our knowledge, HTANGO with the solid‐state phosphorescence quantum yield of 42 % at room temperature is the most efficient phosphor composed of the 1^st/2^nd raw elements only.     

Tailoring Intermolecular Interactions for Efficient Room‐Temperature Phosphorescence from Purely Organic Materials in Amorphous Polymer Matrices

Herein we report a rational design strategy for tailoring intermolecular interactions to enhance room‐temperature phosphorescence from purely organic materials in amorphous matrices at ambient conditions. The built‐in strong halogen and hydrogen bonding between the newly developed phosphor G1 and the poly(vinyl alcohol) (PVA) matrix efficiently suppresses vibrational dissipation and thus enables bright room‐temperature phosphorescence (RTP) with quantum yields reaching 24 %. Furthermore, we found that modulation of the strength of halogen and hydrogen bonding in the G1–PVA system by water molecules produced unique reversible phosphorescence‐to‐fluorescence switching behavior. This unique system can be utilized as a ratiometric water sensor.     

Fluorescent Organic Small Molecule Probes for Bioimaging and Detection Applications

The activity levels of key substances (metal ions, reactive oxygen species, reactive nitrogen, biological small molecules, etc.) in organisms are closely related to intracellular redox reactions, disease occurrence and treatment, as well as drug absorption and distribution. Fluorescence imaging technology provides a visual tool for medicine, showing great potential in the fields of molecular biology, cellular immunology and oncology. In recent years, organic fluorescent probes have attracted much attention in the bioanalytical field. Among various organic fluorescent probes, fluorescent organic small molecule probes (FOSMPs) have become a research hotspot due to their excellent physicochemical properties, such as good photostability, high spatial and temporal resolution, as well as excellent biocompatibility. FOSMPs have proved to be suitable for in vivo bioimaging and detection. On the basis of the introduction of several primary fluorescence mechanisms, the latest progress of FOSMPs in the applications of bioimaging and detection is comprehensively reviewed. Following this, the preparation and application of fluorescent organic nanoparticles (FONPs) that are designed with FOSMPs as fluorophores are overviewed. Additionally, the prospects of FOSMPs in bioimaging and detection are discussed.     

环糊精诱导室温磷光发光机理研究进展

本文综述了环糊精诱导室温磷光发光机理，并对得原子作用及除氧技术作了介绍。     

胶束增稳室温燐光法中化学除氧技术的研究

简便、快速的Na_2SO_3化学除氧技术改善了胶束增稳室温燐光法(MS-RTP)通氮除氧过程费时、繁冗的操作。本文对化学除氧MS-RTP的各种影响条件做了较详细的研究。实验表明,除了SDS、TINO_3、Na_2SO_3用量及温度等因素外,pH对RTP强度和除氧时间也有显著的影响。本文对前人工作作了补充和完善,并对化学除氧机理提出了不同的认识。文中对国产SDS进行了提纯。在荧光光度计上建立了化学除氧MS-RTP法。     

12种嘌呤类化合物的滤纸基质室温燐光法研究

较为详细地研究了１２种嘌呤类化合物以滤纸为基质的室温燐光（ＲＴＰ）光谱特性与分子结构的关系，以及重原子效应和酸度效应对ＲＴＰ的影响。     

6-磺酰氯香豆素的室温燐光特性

通过多种重原子微扰剂和实验条件的选择,成功地实现了C6SCl在数种基质上的RTP发射。发现Pb(Ⅱ)盐是这种RTP发射的最有效的外部重原子微扰剂。在滤纸基质上,以1mol/L Pb(Ac)_2作重原子微扰剂获得了强度高且信/背比亦高的RTP信号,λ_(ex)/λ_(em)=320/496nm。0.2μl点样体积中,C6SCl含量在4～200pmol范围内与RTP信号强度呈良好的线性关系。     

吲哚在无保护溶液体系中的室温燐光

本文研究了吲哚的无保护流体室温燐光(NP-RTP)性质。基于NP-RTP建立起来的分析方法已直接用于鱼中吲哚的测定。方法的线性范围为1.0×10-7~7.0×10-6mol/L,相对标准偏差为2.1%~3.4%。本方法无须保护性介质而仅以KI为重原子微扰剂、Na2SO3为除氧剂即可。0.60 mol/L KI、2.0×10-3mol/L Na2SO3和pH 8.6为方法的最佳测定条件。     

Carboranes Tuning the Phosphorescence of Iridium Tetrazolate Complexes

New iridium tetrazolate complexes containing o‐, m‐, or p‐carboranyl substitution in different positions of a phenylpyridine ligand have been prepared. The carborane isomers and the effect of their substitution position in the tuning of optical properties have been examined. The neutral complexes with the carboranyl substituent on the phenyl ring in meta position relative to the metal exhibit redshifted emission bands in contrast to blueshifts for those with carboranyl in para position. All cationic complexes display evidently blueshifted dual‐peak emission compared with the carborane‐free complex (c‐ TZ ) with a broad single‐peak emission. Introduction of carborane leads to a blueshift over 70 nm relative to c‐ TZ . Carboranes also significantly improve phosphorescence efficiency (Φ_P) and lifetime (τ), that is, Φ_P=0.64 versus 0.21 (c‐ TZ ) and τ=880 ns versus 241 ns (c‐ TZ ). The unique hydrophilic nido‐carborane‐based Ir^III complex nido‐o‐ 1 shows the largest phosphorescence efficiency (abs Φ_P=0.57) among known water‐soluble iridium complexes, long emission lifetime (τ=4.38 μs), as well as varying emission efficiency and lifetime with O₂ content in aqueous solution. Therefore, nido‐o‐ 1 has been used as an excellent oxygen‐sensitive phosphor for intracellular O₂ sensing and hypoxia imaging.     

纸基质室温燐光法测定痕量6-苄氨基嘌呤的研究

本文经实验发现6-苄氨基嘌呤吸附在滤纸基质上能够发射出室温燐光。较详细地研究了其室温燐光特性。实验表明,在弱碱性条件下,以KI-NaAc作混合重原子微扰剂时,6-苄氨基嘌呤能产生较强的燐光发射,在此条件下,6-苄氨基嘌呤浓度与室温燐光发射强度之间在1×10~(-5)～9×10~(-4)mol/L范围内呈良好的线性关系。检出限为8ng/斑点。