TADF敏化荧光策略构建高效、窄光谱发光电化学池器件

基于新一代热活化延迟荧光(Thermally activated delayed fluorescence,TADF)发光材料的发光电化学池(Light-emitting electrochemical cells,LECs)成为新兴的研究方向而受到关注。由于TADF发光材料电荷分离态的激子属性,该类LECs器件发光光谱半峰宽往往达到100 nm以上,难以满足LEC高色纯度的需求。鉴于此,本文尝试将TADF敏化荧光(TADF-sensitized fluorescence,TSF)的激子管控策略应用到LECs领域当中。通过筛选合适的传输主体、TADF敏化剂、高吸光系数荧光染料和离子液体固态电解质为LEC的发光层,我们成功构建了高效TSF型的LECs器件。最终获得的TSF-LECs器件峰值外量子效率(The highest external quantum ef-ficiency,EQEmax)达到3.7%,峰值亮度(The peak luminance,Lmax)达到2285 cd·m^(-2)。与TADF-LECs的参比器件相比,TSF-LECs器件的光谱半峰宽(Full width at half maximum,FWHM)从106 nm降低至38 nm。本文还详细讨论了所制备TSF-LECs器件中的能量转移和激子损失途径。该工作为进一步优化设计TSF-LECs材料和器件奠定了基础。

基于器件结构提高TADF-OLED器件的发光性能

为了提高以TADF材料作为主体、天蓝色荧光材料作为客体的混合薄膜的OLED器件光电性能,我们调整了器件结构,使主体材料发挥其优势。制备了基本结构为ITO/NPB(40 nm)/DMAC-DPS∶x%BUBD-1(40 nm)/Bphen(30 nm)/LiF(0.5 nm)/Al的OLED器件。研究了主-客体材料在不同掺杂浓度下的OLED器件的光电特性。为了提高主体材料的利用率,在空穴传输层和发光层之间加入10 nm的DMAC-DPS作为间隔层;然后,在阳极和空穴传输层之间加入HAT-CN作为空穴注入层,形成HAT-CN/NPB结构的PN结,有效降低了器件的启亮电压(2.7 V)。测量了有无HAT-CN的单空穴器件的阻抗谱。结果表明,在最佳掺杂比例(2%)下,器件的外量子效率(EQE)达到4.92%,接近荧光OLED的EQE理论极限值;加入10 nm的DMAC-DPS作为间隔层,使得器件的EQE达到5.37%;HAT-CN/NPB结构的PN结有效地降低了器件的启亮电压(2.7 V),将OLED器件的EQE提高到5.76%;HAT-CN的加入提高了器件的空穴迁移率,降低了单空穴器件的阻抗。TADF材料作为主体材料在提高OLED器件的光电性能方面具有很大的潜力。

器件结构对蓝光TADF-OLED光电性能的影响

采用真空热蒸镀法,以热活化延迟荧光(TADF)材料为主体材料、发光材料为客体材料制备混合薄膜发光层,以提高蓝色荧光材料的OLED发光效率。当OLED器件结构为ITO/HAT-CN(5 nm)/TAPC(30 nm)/TCTA(10 nm)/Blue-Or:DMAC-DPS(30%,30 nm)/DPEPO(10 nm)/Bphen(30 nm)/LiF(1 nm)/Al(70 nm)时,器件的光电性能最佳。此蓝光TADF-OLED器件的外量子效率为12.39%,电流效率为21.68 cd/A,功率效率为19.44 lm/W。研究发现改变TADF-OLED的掺杂主体材料和添加空穴注入层均可有效地提高器件的光电特性。实验内容与该领域的前沿科学研究相结合,OLED器件的光电性能稳定、实验现象显著,适于引入本科实验课程。通过该综合实验学生可以夯实实验基础、了解研究热点、掌握最新的科研动态。

Aggregation-induced emission luminogen for in vivo three-photon fuorescence lifetime microscopic imaging

Compared with visible light,near infrared(NIR)light has deeper penetration in biological tisues.Three-photon fuorescence microscopy(3PFM)can effectively utilize the NIR excitation to obtain high-contrast images in the deep tisue.However,the weak three photon fluorescence signals may be not well presented in the traditional fuorescence intensity imaging mode.Fluorescence lifetime of certain probes is insensitive to the intensity of the excitation laser.Moreover,fluorescence lifetimne imaging microscopy(FLIM)can detect weak signals by utilizing time correlated single photon counting(TCSPC)technique.Thus,it would be an improved strategy to combine the 3PFM imaging with the FLIM together.Herein,DCDPP-2TPA,a novel agegation-induced emission luminogen(AIEgen),was adopted as the fluorescent probes.The three-photon absorption cros-section of the AlEgen,which has a deep-red fluorescence emission,was proved to be large.DCDPP-2TPA nanoparticles were synthesized,and the three photon fluorescence lifetime of which was measured in water.Moreover,in vrivo thre-photon fuorescence lifetime microscopic imaging of a craniotomy mouse was conducted via a home made optical system.High contrast cerebrovascular images of different vertical depths were obtained and the maximun depth was about 600 pumn.Even reaching the depth of 600 pum,tiny capillary vessels as small as 1.9 pum could still be distinguished.The three photon fuorescence lifetimes of the capillaries in some representative images were in accord with that of DCDPP-2TPA nanoparticles in water.A vivid 3D reconstruction was further organized to present a wealth of lifetime information.In the future,the combination strategy of 3PFM and FLIM could be further applied in the brain functional imaging.

基于TADF共掺杂的蓝光OLED器件性能研究

为提升蓝光OLED的发光性能,采用DPEPO和DMAC-DPS两种热活化延迟荧光(TADF)材料构成的主客体掺杂结构作为蓝光OLED器件的发光层,研究器件结构、客体掺杂浓度等因素对器件性能的影响。实验结果表明:采用MoO 3薄膜作为空穴注入层有助于增强空穴注入和传输能力,进而提升器件性能。当DMAC-DPS掺杂浓度为30%时,器件性能是最优的,最大亮度为5650 cd/m 2,最大外量子效率(EQE)为8.63%。掺杂浓度进一步增大会导致器件性能的衰退,可能是因为高浓度导致的激子淬灭导致的。TADF有助于提升蓝光OLED器件的性能并有望应用于商业化的蓝光OLED器件中。

Synthesis,Crystal Structure and Photoluminescence of a TADF Cuprous Complex

A four-coordinate mononuclear cuprous complex oCBP-Cu-Pym(1, oCBP =1,2-bis(diphenylphosphine)-nido-carborane, Pym = 2-methyl-6-(1 H-pyrazol-1-yl)pyridine) was synthe-sized and characterized by elemental analysis, NMR, UV-Vis and X-ray single-crystal structure analysis. It crystallizes in monoclinic space group C2/c with a = 28.4182(8), b =16.2994(4), c = 22.2708(5) ?, β = 127.219(2)°, V = 8214.8(3) ?3, Z = 8, Mr = 766.92, ρcalc = 1.24 g/cm3, F(000) = 3160, μ = 2.30 mm–1, GOOF = 1.063, the final R = 0.0700 and wR = 0.1903 for7158 observed reflections with I > 2σ(I). The Cu(I) ion adopts a highly distorted tetrahedral geometry defined by two nitrogen and two phosphorous atoms. Under UV 365 nm at room temperature, this complex exhibits green emission with maximum emission peak at 516 nm,lifetime 32.4 μs and quantum yield(ф = 0.461) in the solid state. Photophysical investigation suggests that the emission of complex 1 at room temperature was attributed to TADF, which is strongly supported by theoretic calculation.

Detecting benign uterine tumors by autofuorescence lifetime imaging microscopy through adjacent healthy cervical tissues

The endogenous fluorophores such as reduced nicotinarmide adenine dinucleotide(phosphate)(NAD(P)H)and favin adenine dinucleotide(FAD)in cells and tissues can be imaged by fuo-rescence lifetime imaging microscopy(FLIM)to show the tisute morphology features,as well as the biomolecular changes in microenvironment.The two important coenzymes in cellular metabolism,NAD(P)H and FAD,can be used to monitor the cellular metabolic status.This work proposed a novel method to study the uterine metabolism at the adjacent site of healthy cervix.It was found that the benign uterine tumors such as leiomyomas and adenomyosis with abnormal cell growth can be detected by measuring the fluorescence lifetime of NAD(P)H and FAD in adjacent healthy cervical tisues.This method opened a novel strategy for alicted women to undergo the cervical biopsies instead of hysterectomies for detecting tumors,which can preserve the fertility of patients.The FLIM studying on NAD(P)H and FAD indicated the correlation between metabolism and some diseases,including diabetes,hyperthyroidism and obesity.It was also suggested that the metabolic level might be quite different for a patient with a malignant tumnor history.

Biomedical optical properties of color light and near-infrared fuorescence separated-merged imager

Objective:We study the biomedical optical properties of the color light and near-infrared fluorescence separated-merged imager.Materials and Methods:The color light and near infrared fuorescence separated merged imager can iluninate the visible light and the near infrared light of 760±10 nm,receiving the reflected light and 835±10 nm near-infrared fuorescence,and display the color,fuorescence and merge inage.ICG solution of different concentration,including standing time,was allocated to study the best inaging condition in vitro,and the depth of fuorescence penetration was studied with 5%agarose gel;the imaging characteristics of the imager was studied using SD rat;and then the SLNs tracing in 4 cases of penile carcinoma was performed.Results:When the concentration of ICG is 13.11 pumol/L,the fuorescence intensity and the merge imnage are the best.The maximun depth of fluorescence imaging is 9 mm in 5%agarose gel,while the bone has the greatest influence on it.The SLNs tracing shows that the imager can locate the SLNs in vitro,to achieve perioperative navigation during biopsy.Conclusion:There are many factors that affect the imaging effect,but the imaging effect of the imager meets the requirement of vision in a wide range,and can effectively trace the SLNs in perioperative period.

Synthesis,Crystal Structure,and Photo-and Electro-luminescence of a TADF Cu(Ⅰ)Complex

A four-coordinate mononuclear cuprous complex [Cu（ac1m）POP]BF4·0.5（C6H14）· 0.5（C2H5OH）（1, ac1 m = 2-（2-ethoxyphenyl）-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline, POP = bis[2-（dipenylphosphino）phenyl]ether） was synthesized and characterized by elemental analysis, NMR, UV-vis, cyclic voltammetry and X-ray single-crystal structure analysis. It crystallizes in monoclinic space group P21/c with a = 17.0546（19）, b = 15.4650（17）, c = 23.685（2） A, β = 104.007（11）°, V = 6061.1（12）A^3, Z = 4, Mr = 1171.46, Dc = 1.284 g/cm^3, F（000） = 2432, μ = 1.50 mm^–1, GOOF = 1.070, the final R = 0.059 and wR = 0.1640 for 8952 observed reflections with I 〉 2σ（Ⅰ）. Compound 1 is composed of a BF4-anion and a [Cu（ac1m）POP]^＋ cation. The Cu（Ⅰ） ion adopts a tetrahedral coordination geometry defined by two nitrogen and two phosphorous atoms. The complex exhibits yellow luminescence with maximum emission peaks at 546 nm, lifetimes 15.1 μs and quantum yields（ф = 0.130） at room temperature. The complex displays thermally activated delayed fluorescence（TADF） at room temperature, which is proved experimentally and theoretically. And the organic light-emitting diode（OLED） with 1 as the light emitting material has the maximum current efficiency of 5.86 cd/A and the highest brightness of 3215 cd/m^2.

新型TADF聚合物结构设计及性质研究

为研究新型TADF聚合物结构及性质,进一步推进TADF聚合物的应用及发展,该文以二苯甲酮为受体、以9.9-二甲基吖啶为给电子体,设计了聚合物PABP-1和PABP-2的合成试验,并对聚合物PABP-1、PABP-2和ABP这3种分子进行密度泛函理论(DFT)计算和光物理性能分析。试验研究结果表明:1)ABP与聚合物PABP-1均有可能具备TADF性能。2)在THF稀溶液和纯薄膜状态下,聚合物PABP-1、PABP-2的发射峰出现红移并且聚合物PABP-1的红移大于聚合物PABP-2。3)聚合物PABP-1、PABP-2和ABP可以作为TADF的发光材料。4)混合溶液中的含水量不断提升,3种分子的发光强度呈现出先减弱、后增强的趋势,聚合物PABP-1的性能更好。

新型TADF材料可以使外量子效率提高3倍

一国际联合研究团队成功研制出一种新型热激发延迟荧光（TADF）材料,这是世界上首次通过系间窜越从单重态激子到三重态激子发射出绿色至深红色光波。这项研究结果将推动白色TADF发光设备在室内外的应用研究。在过去的几十年中,对有机电致发光器件（OLED）的研究取得了很大进展。实际上,很多类型的OLED获得了广泛的市场应用,从照明光源到智能手机等都有OLED的身影。

基于喹喔啉和吡啶并吡嗪及咔唑和二苯胺衍生物电子给体-受体结构荧光材料的合成和光电性能

通过α-二酮与邻苯二胺、吡啶二胺缩合反应,构建了喹喔啉和吡啶并吡嗪衍生物作为电子受体,分别以二苯胺、咔唑衍生物为电子给体,合成了4个具有电子给体-电子受体结构的氮杂环荧光材料F1~F4。通过低温荧光/磷光光谱、荧光寿命测试,结合密度泛函理论计算可知,F1~F4均为荧光小分子。室温荧光光谱结果表明,利用电子给体和受体的电子效应不同可以调控材料的发光颜色,其中三苯胺相对于苯基咔唑的供电子能力更强,表现为F1比F2、F3比F4红移现象更加明显;而吡啶并吡嗪具有多氮的缺电子结构,与喹喔啉相比共轭程度增加,导致F3比F1、F4比F2发生的斯托克斯位移数值增大。总之,F1~F4的甲苯溶液最大荧光光谱发射峰位于529、464、568和507 nm,荧光寿命分别为12.21、2.61、9.76和6.03 ns,荧光量子效率最高可达98.2%,具有良好的发光性能。将F1~F4发光材料掺杂在主体材料中制备了有机电致发光二极管DF1~DF4。所得器件DF1和DF3性能更好,最大电流效率分别为13.38和11.98 cd·A-1,且最大外量子效率分别达到4.8%和4.5%。

关于段炼和张东东“全氘代提高蓝光热激活延迟荧光发射器的效率和稳定性”文章的评论(Nature Photonics,2024,29)

有机电致发光二极管(Organic light-emitting diode, OLED)是目前最具有发展前景的显示技术之一,而蓝光OLED的寿命和稳定性一直是亟需解决的问题。段炼和张东东在《自然光子学》上发表的成果表明,对蓝光热激活延迟荧光(Thermally activated delayed fluorescence, TADF)分子进行全氘代的策略,在保持其高电致发光效率的同时,可以显著提升其器件的寿命。

Development and application of a SYBR Green I fuorescent PCR assay for the diferentiation of genotypes I and II African swine fever viruses

African swine fever(ASF)is a highly fatal hemorrhagic disease afecting domestic pigs caused by African swine fever virus(ASFV).Genetic analysis of ASFV isolates to date has identifed 24 geographically related genotypes with various subgroups,but only genotype I and II ASFVs have been reported outside Africa.ASFV genotype II and genotype I viruses were reported in China in 2018 and 2021,respectively.In this study,unique and highly conserved noncoding regions were found between MGF_505-9R and MGF_505-10R in the 188 genomes of ASFV genotypes I and II.A pair of primers was designed on the basis of this region.By optimizing the reaction system and conditions,a SYBR Green I fuorescence PCR assay that can distinguish between ASFV genotypes I and II was established,and the sensitivity,reproducibility and specifcity were evaluated.The detection limit was 1 TCID_(50)/0.1 mL for both genotypes,with no cross-reactivity observed with other common pig pathogens.The intra-and interbatch variation coefcients were both less than 1.2%.Clinical sample detection analysis revealed 47 positive cases out of 100,including 3 for genotype I and 44 for genotype II,aligning with results from the WOAH-recommended and national standard methods.The method developed in this study allows for the diferentiation of ASFV genotypes I and II without the need for genome sequencing,ofering a convenient and rapid approach for ASFV detection and genotype identifcation.

猪肺炎支原体SYBR Green Ⅰ实时荧光定量PCR检测方法的建立与应用

为建立一种快速高效的猪肺炎支原体(Mycoplasma hyopneumoniae,Mhp)检测方法,根据NCBI公布的Mhp保守序列设计4对特异性引物,依据4对引物的荧光定量PCR检测结果及拟合曲线进行相关性分析,筛选出最佳引物(SX4),建立了Mhp SYBR Green Ⅰ实时荧光定量检测方法。该方法可特异性检测Mhp,对猪圆环病毒2型、猪细小病毒、猪伪狂犬病病毒、副猪嗜血杆菌4型及链球菌2型等病原均无特异性扩增;最佳引物SX4检测的灵敏度可达4.9×10^(1) copies/μL,组内和组间变异系数均小于2%。该方法可稳定检测出工艺生产抗原和市售疫苗中的Mhp菌量。试验表明,本研究成功建立了Mhp SYBR Green Ⅰ实时荧光定量检测方法,其特异性强、灵敏度高、重复性好,可用于Mhp疫苗抗原生产和临床疫苗中的Mhp菌量检测。

利用GFP表达系统检测球孢白僵菌侵染昆虫过程

绿色荧光蛋白(GFP)作为一种重要的报告基因,在病原菌和寄主之间的互作研究中具有良好的应用前景。利用草丁膦抗性基因bar为筛选标记,构建了组成性表达绿色荧光蛋白基因egfp的载体pBG,并转入球孢白僵菌获得成功表达。将转化子接种菜青虫进行生物测定表明,组成性表达egfp不影响球孢白僵菌的毒力。进一步利用冰冻切片和荧光显微观察技术监测球孢白僵菌侵染寄主行为,结果显示,通过荧光观察可清楚的检测到病原菌在昆虫体表的附着、菌丝穿透体壁以及菌丝从寄主体内长出等侵染过程。由此表明,GFP可有效用于球孢白僵菌的遗传标记,进行病原菌的鉴别、侵染致病机理及相关功能基因的表达模式研究。

高效白光OLED器件进展及性能分析

分析了白光OLED照明的优势。从器件的角度,介绍在OLED中实现白光的方法,并从不同的方面对白光OLED器件进行了分类。分析了各类器件结构的特点,并介绍了白光OLED器件的最新研究进展和性能及技术发展趋势。

水盐胁迫对沙枣幼苗叶绿素荧光参数和色素含量的影响

在不同水分和盐分胁迫条件下测定2个种源沙枣的叶绿素含量、叶绿素荧光参数Fv/Fm和Fv/F0的变化。结果表明：随着胁迫的增加,2个种源的沙枣叶绿素含量、Fv/Fm和Fv/F0都表现出先增加后降低的趋势;在水分梯度为50%~55%和盐分梯度为0.1 mol/L时2个种源的叶绿素含量、Fv/Fm和Fv/F0值分别达到最大值;随胁迫时间增加,水分胁迫下包头种源叶绿素含量下降幅度比赤峰种源高出29.28%,而Fv/Fm值和Fv/F0值最大改变量分别为赤峰种源的1.25倍和6.62倍;盐分胁迫下包头种源沙枣的叶绿素含量下降幅度比赤峰种源高出25.26%,而Fv/Fm值和Fv/F0值最大改变量分别为赤峰种源的2.38倍和3.05倍。这说明水分和盐分胁迫对包头种源沙枣的叶绿素含量及其荧光参数的影响高于对赤峰种源的影响。

基于荧光素硫代酰肼类Hg^2＋荧光探针的合成及在生物成像中的应用

利用希夫碱反应,在荧光素硫代酰肼中引入对羟基苯甲醛、吡咯甲醛等醛基化合物,制得了能特异检测汞离子的3种荧光染料探针TFP3,TFP4及TFP5.研究发现,当加入7.5μmol/L的Hg^(2+)后,TFP3,TFP4和TFP5的荧光光谱530 nm处均出现了约高于30倍的荧光增强,其检出限分别为7.22×10^(-8),1.03×10^(-7)和1.28×10^(-8)mol/L.另外,细胞成像实验结果表明,该探针具有良好的生物相容性和低毒性,在生物体系中具有实际应用价值.

一株产碳酸酐酶附生菌对铜绿微囊藻(Microcystis aeruginosa)生长的影响

为研究生长环境中微生物对铜绿微囊藻碳代谢的影响,本文分析太湖典型微囊藻水华样品附生菌中产碳酸酐酶(CA)细菌的比例,结果显示CA菌占11.6%;从微囊藻群体中分离获得了一株高胞外CA附生菌P201,通过ITS基因鉴定,该菌为一株荧光假单胞菌(Pseudomonas fluorescence).并研究了该菌在不同浓度HCO3-条件下对铜绿微囊藻生长的影响,结果表明无论是高HCO3-浓度还是低HCO3-浓度环境中,加入该菌对铜绿微囊藻的生长均有促进作用,说明产CA酶附生菌对铜绿微囊藻的生长有一定的促进作用.