Assembling Tunable Time-Resolved Fluorescence Layer onto Nano-Gold

The assembling of a coating of time-resolved fluorescent chelator BSPDA （ abbreviated for 4, 7-bis （ sulfhydrylphenyl）-1, 10-phenanthroline-2, 9-dicarboxylic acid） onto a nano-gold layer was demonstrated. First, BSPDA was synthesized by simple procedures, and then an approach was developed to immobilize BSPDA onto the nano-gold layer deposited on a silane modified glass substrate, whereby europium ion （Ⅲ, Eu^3＋ ） was captured and released owing to the interactive process of complexation and dissociation between BSPDA functionalized coating and Eu^3＋ solution. The fluorescence spectra and related lifetimes were determined. Also, the BSPDA functionalized coating＇s specific complexation with Eu^3＋ on the BSPDA assembly layer and the nonspecific adsorption of Eu^3＋ on the nano-gold layer were compared. These results allowed a selective complexation of Eu^3＋ by assembling a BSPDA chelating layer on the nano-gold layer; thus, a tunable time-resolved fluorescent layer was covalently attached, The results of the nanoparticle assembling and probing （or labeling） processes to specific bio-systems were very interesting and had significant implications to time-resolved-fluorescence-based detection on biosensor surfaces such as DNA chip and to arrayed light display devices.

Detection of K in soil using time-resolved laser-induced breakdown spectroscopy based on convolutional neural networks

One of the technical bottlenecks of traditional laser-induced breakdown spectroscopy(LIBS) is the difficulty in quantitative detection caused by the matrix effect. To troubleshoot this problem,this paper investigated a combination of time-resolved LIBS and convolutional neural networks(CNNs) to improve K determination in soil. The time-resolved LIBS contained the information of both wavelength and time dimension. The spectra of wavelength dimension showed the characteristic emission lines of elements, and those of time dimension presented the plasma decay trend. The one-dimensional data of LIBS intensity from the emission line at 766.49 nm were extracted and correlated with the K concentration, showing a poor correlation of R_c^2?=?0.0967, which is caused by the matrix effect of heterogeneous soil. For the wavelength dimension, the two-dimensional data of traditional integrated LIBS were extracted and analyzed by an artificial neural network(ANN), showing R_v^2?=?0.6318 and the root mean square error of validation(RMSEV)?=?0.6234. For the time dimension, the two-dimensional data of time-decay LIBS were extracted and analyzed by ANN, showing R_v^2?=?0.7366 and RMSEV?=?0.7855.These higher determination coefficients reveal that both the non-K emission lines of wavelength dimension and the spectral decay of time dimension could assist in quantitative detection of K.However, due to limited calibration samples, the two-dimensional models presented over-fitting.The three-dimensional data of time-resolved LIBS were analyzed by CNNs, which extracted and integrated the information of both the wavelength and time dimension, showing the R_v^2?=?0.9968 and RMSEV?=?0.0785. CNN analysis of time-resolved LIBS is capable of improving the determination of K in soil.

Time-resolved spectroscopy for 5s^('4)D_(7/2) state transitions undergoing electron–ion recombination in femtosecond laser-produced copper plasma

In the femtosecond laser-produced Cu-plasma, the transient transition dynamics that the excited state 5s4D7/2 via electron-ion recombination transfers to 4p4F9/20 （465.11 nm, Λ1 line） and 4p4D7/20 （529.25 nm, Λ2 line） states are investigated by using the time-resolved spectroscopy. The occupation number and relevant lifetime of the excited state 5s4D7/2, the temporal evolutions of spectral intensities for Λ1 line and Λ2 line emissions are demonstrated to be in direct proportion to the employed laser intensity, which reveals the transient features of transition dynamics clearly differing from that resulted in the traditional collision excitation. Furthermore, some unique characteristics for Λ1 and Λ2 transitions stemming from electron-ion recombination are examined in detail.

Complexation of radionuclide ^152＋154Eu(Ⅲ) with alumina-bound fulvic acid studied by batch and time-resolved laser fluorescence spectroscopy

To contribute to the understanding of Eu(Ⅲ)interaction properties on hydrous alumina particles in the absence and presence of fulvic acid(FA),the complexation properties of Eu(Ⅲ)with hydrous alumina,FA and FA-alumina hybrids are studied by batch and time-resolved laser fluorescence spectroscopy(TRLFS)techniques.The continuous increase in the fluorescence lifetime of Eu-alumina and Eu-FA with increasing pH indicates that the complexation is accompanied by decreasing number of hydration water in the first coordination sphere of Eu(Ⅲ).Eu(Ⅲ)is adsorbed onto alumina particles as outer-sphere surface complexes of≡(Al-O)-Eu·(OH)·7H_2O and≡(Al-O)-Eu·6H_2O at low pH values,and as inner-sphere surface complexes as≡(Al-O)_2-Eu^+·4H_2O at high pH.In FA solution,Eu(Ⅲ)forms complexes with FA as(COO)_2Eu^+(H_2O)_x and the hydration water number in the first coordination sphere decreases with pH increasing.The formation of≡COO-Eu-(O-Al≡)·4H_2O is observed on FA-alumina hybrids,suggesting the formation of strong inner-sphere surface complexes in the presence of FA.The surface complexes are also characterized by their emission spectra[the ratio of emission intensities of^5D_0→~7F_1(λ=594nm)and^5D_0→~7F_2(λ=619nm)transitions]and their fluorescence lifetime.The findings is important to understand the contribution of FA in the complexation properties of Eu(Ⅲ)on FA-alumina hybrids that the clarification of the environmental behavior of humic substances is necessary to understand fully the behavior of Eu(Ⅲ),or its analogue trivalent lanthanide and actinide ions in natural environment.

TIME-RESOLVED FLUORESCENCE SPECTROSCOPY OF HEMATOPORPHYRIN DERIVATIVE LASER No. 3

Ⅰ. INTRODUCTIONPhotodynamic therapy (PDT) which utilizes hematoporphyrin derivative (HpD) as a photosensitizing drug has increasingly being used for the local treatment of malignant tumors. The success of this method is attributed to the ability of HpD to accumulate to

Preliminary Study of the CAS-LIBB Single-Particle Microbeam Ⅱ Endstation: Ⅰ. Proposed Multi-Dimensional Quantitative Fluorescence Microscopy

Single-particle microbeam as a powerful tool can open a research field to find answers to many enigmas in radiobiology. A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering （LIBB）, Chinese Academy of Sciences （CAS）, China. However there has been less research activities in this field concerning the original process of the interaction between low-energy ions and complicated organisms. To address this challenge, an in situ multi-dimensional quantitative fluorescence microscopy system combined with the CAS-LIBB single-particle microbeam II endstation is proposed. In this article, the rationale, logistics and development of many aspects of the proposed system are discussed.

Intense Long-Lived Fluorescence of 1,6-Diphenyl-1,3,5-Hexatriene: Emission from the S₁-State Competes with Formation of O₂Contact Charge Transfer Complex

The fluorescence kinetics of 1,6-diphenyl-1,3,5-hexatriene (DPH) dissolved in cyclohexane was investigated as a function of temperature, concentration and 355 nm excitation pulse energy. At concentrations above 2.5 μM and excitation energies above 1 mJ a long-lived, very intense emission, which appears within less than 5 ns and lasts up to 70 ns, is observed. During the first 50 ns the decay does not follow an exponential but rather a linear behaviour. In oxygen saturated solutions the long-lived emission is suppressed and solely short-lived fluorescence with τ 1-state and competes with the formation of DPH-O2 contact charge-transfer complexes and intersystem crossing which both quench the fluorescence. Our investigations show that even the small amount of oxygen dissolved in nitrogen saturated solutions has a distinct influence on the fluorescence kinetics of DPH.

Communication Chain-foldability effect on coaggregation Evidence derived from time-resolved fluorescence spectroscopy

Very recently,we have proposed that all culprit molecules of arteriosclerosis mightpossess a common and measurable inherent property,namely,a coaggregating ten-dency.Extensive kinetic measurements of these tendencies in terms of △CAgC valueshave led to a new and surprising observation,i.e.,the cholesteryl ester with a longsaturated 18-carbon chain(CE-18)actually has a much smaller tendency towardcoaggregation than that of the ester with a“short”8-carbon chain(CE-8).Thisstate of affairs has been coined as the“chain-foldability effect”,i.e.,the 18-carbon

动物源食品中孕酮激素残留的时间分辨荧光免疫分析法的建立

该研究以孕酮为研究对象,设计并制备了新抗原,通过动物免疫得到特异性兔抗体,基于所得抗原和抗体,进一步优化了抗原抗体浓度、反应缓冲液种类及其pH值等关键参数,最终在国内首次建立了用于动物性食品中性激素孕酮残留快速检测时间分辨荧光免疫分析法(TRFIA)。该研究确定最优实验条件为:抗原0.30μg/mL、铕标抗体0.40μg/mL、pH值7.2的TBST工作缓冲液,并建立标准曲线,方法的线性范围为0.46~6.94μg/L,IC_(50)达1.79μg/L,与睾酮交叉反应率为1.25%,与雌二醇、雌三醇等激素无交叉反应。实际样品的平均添加回收率为82.0%~113.0%,批内批间变异系数<5%,与高效液相色谱法(HPLC)检测结果的相关性良好(r2=0.988)。结果表明该研究所建立的TRFIA检测方法准确可靠、特异性好、灵敏度高,完全可用于动物源食品中孕酮残留的快速检测。

Energy transfer mechanism of PBS-thylakoid complexes——By time-resolved fluorescence spectra technique

IN a previous paper, we have studied the energy transfer mechanism among the PBS-thy-lakoid complex in detail by using steady-state spectra and deconvolution techniques. The ex-perimental results indicated that the energy transfer from PBS to two reaction centers of PS Ⅰand PS Ⅱ were parallel, and confirmed the model which was suggested by Mullineaxu.

太赫兹光谱技术在表征双相无机钙钛矿材料特性中的应用

钙钛矿材料制备过程中的成分监控与表征对材料科学与钙钛矿技术的发展至关重要。采用时间分辨太赫兹光谱(TRTS)技术对双相CsPbBr3-CsPb2Br5薄膜材料在光泵浦作用下的光致电导特性进行了详细分析。通过观察和区分不同成分的Cs-Pb-Br三元钙钛矿材料的光谱特征,确认了不同声子模式的来源。使用Drude-Smith模型的延伸模型对样品的光致电导进行拟合分析,进一步探究了薄膜材料的载流子动力学过程以及晶体结构的变化过程。本实验为太赫兹时域光谱技术在钙钛矿鉴别中的应用提供了新的视角,也为钙钛矿材料在光伏领域的潜在应用提供了坚实的理论依据。

STEADY-STATE AND TIME-RESOLVED FLUORESCENCE STUDY OF TRIPLE EXCIPLEX IN THE SYSTEM OF POLYACENAPHTHALENE AND TEREPHTHALIC DIMETHYLESTER

Triple exciplex formed between polyacenaphthalene and terephthalic dimethylester （TDE） has been studied by means of the steady-state and time-resolved fluorescence spectra. The theoretical model of the triple exciplex formation for a flexible polymer chain in a dilute solution has been proposed. The fluorescence decays of the monomer, the exciplex and the triple exciplex obey a double exponential rule in the pbotophysical processes of the triple exciplex formation. The association rate constant of the exciplex formation is k3=6.0×109s-1（mol/L）-1; the association rate constant of the triple exciplex formation is k6=5.2×107s-1. A mechanism for the triple exciplex formation from the exciplex to the triple exciplex has been proved through the noncrystal films corresponding to the same concentrations of the solution systems and the fluorescence lifetimes of the intramolecular excimer.

利用时间分辨荧光免疫层析法同时定量检测玉米中的伏马毒素B_(1)、B_(2)和B_(3)

建立了一种可同时定量检测玉米中伏马毒素B_(1)、B_(2)和B_(3)的时间分辨荧光免疫层析方法。利用活化酯法制备时间分辨荧光微球和伏马毒素抗体的偶联物,将伏马毒素抗原包被到硝酸纤维素膜上作为T线,通过优化不同T线包被条数,最终建立伏马毒素竞争性免疫层析方法。并对所建立方法的灵敏度、特异性、准确度、精密度和与国标方法分析结果的相关性进行评价。包被两条T线建立的检测方法检出限为107.68~168.28μg/kg,定量限为283.46~444.63μg/kg;与伏马毒素B_(1)、伏马毒素B_(2)和伏马毒素B_(3)的交叉反应率分别为100%、85.59%和72.72%,与其它5种常见的真菌毒素均无明显交叉;加标回收率范围88.37%~117.42%,变异系数小于10%;该方法与国标方法GB 5009.240-2016中规定的免疫亲和柱净化-高效液相色谱法(IAC-HPLC)检测结果的符合度在92.17%~107.21%之间。建立的时间分辨荧光免疫层析检测方法能满足对玉米中伏马毒素B_(1)、B_(2)和B_(3)的现场快速定量检测。

TIME-RESOLVED FLUORESCENCE STUDY OF TRIPLE EXCIPLEX FORMED IN THE SYSTEM OF POLY(2-VINYL) NAPHTHALENE AND TEREPHTHALIC DIMETHYLESTER

An intramolecular excimer of poly（2- vinyl） naphthalene was formed by non-adjacentchromophores interaction, then a triple exciplex was formed by interaction with the acceptormolecule further in dilute solution. The lifetime of the intramolecular excimer of poly（2-vinyl） naphthalene, τ2 = 18.83 ns and the rate constant for the triple exciplex formation,k7 = 4. 18× 109 （mol/L）-1s-1, under diffusion-control were measured. An excimer or anexciplex could be an intermediate of the triple exciplex formation. A theoretical model ofthe triple exciplex formation is proposed.

高灵敏度玉米赤霉烯酮时间分辨荧光快速定量检测卡的研发和应用

成功研发了一种灵敏度高、准确度好、快速、简易的双T线的玉米赤霉烯酮(ZEN)时间分辨荧光快速定量检测卡。通过对比ZEN检测卡检测线数量(单T线、双T线)的灵敏度,主要利用双T线的增补作用优势抬高灵敏度。对比了独立C线、非独立C线体系工艺,利用非独立C线工艺,C值与T值呈现负相关来提高灵敏度。筛选出羊抗鼠-自身鼠抗非独立C线工艺,在其基础上进一步筛选标记抗体量(5、10、20、30μg/mL),选择标记抗体量10μg/mL效价25429,10~500μg/kg抑制率33.57%~98.30%,灵敏度、效价最佳。用液相色谱与玉米赤霉烯酮(ZEN)时间分辨荧光快速定量检测卡同时检测不同基质的样本,两者的符合度很高,准确度在90.89%~119.33%,浓度CV6.18%。研究表明,用荧光层析检测卡检测粮食谷物中玉米赤霉烯酮的分析方法稳定性好,货架期符合要求,可测范围宽,具有很好的应用前景。

高灵敏度呕吐毒素时间分辨荧光快速定量检测卡的研发和应用

利用时间分辨荧光快速定量检测技术采用稀有元素“铕”作为示踪物,开发出一种用于检测粮食谷物中的呕吐毒素含量的高灵敏度呕吐毒素时间分辨荧光快速定量检测卡。交联剂碳二亚胺(EDC)用量25 μL/mL、抗体量10 μg/mL标记脱氧雪腐镰刀菌烯醇DON单抗并用硼酸-硼砂缓冲液(12 mmol/L,pH 7.27)体系作为喷膜稀释液喷于结合垫上。Tris-HCl (10 mmol/L,pH 7.0)作为T线划膜液体系,羊抗鸡二抗以及呕吐毒素抗原均匀地划于硝酸纤维素膜(NC)上质控线和检测线的位置,C线划膜浓度0.2 mg/mL, T2线划膜浓度0.05 mg/mL, T1线划膜浓度0.15 mg/mL。依次将样品垫、结合垫、NC膜和吸水纸组装切割装入检测卡中。测试结果表明定量值250 μg/kg的抑制率为39.54%。并进一步使用检测卡检测来自国家粮食和物资储备局科学研究院、江苏质检中心以及南京微测生物科技有限公司的18个质控样本,样本类型覆盖玉米、小麦以及小麦制品。与液相色谱法检测出的结果相符,准确度的平均值高达102.41%。该检测方法适合用于现场的快速筛查,具有广阔的市场应用前景。

S100B时间分辨荧光免疫检测试剂盒的制备及性能评价

目的:制备一种快捷、准确、定量检测血清中S100B蛋白浓度的时间分辨荧光免疫检测试剂盒,并对其进行性能评价。方法:使用时间分辨荧光微球标记的抗S100B多克隆抗体及兔IgG抗体、标记垫、样品垫、S100B硝酸纤维素膜板、吸水纸制备试纸条,组装卡壳得到S100B时间分辨荧光免疫层析试剂盒。通过标准曲线、准确度、最低检测限、线性区间、特异度、重复性、稳定性等检测对该试剂盒进行性能评估。采用该试剂盒对某地区199例健康者血清及血浆样本的参考区间进行研究,并采用同步盲法测试该试剂盒与罗氏Elecsys S100检测试剂盒的临床应用性能,评估2种试剂盒对于142例样本检测结果的一致性。结果:该试剂盒所得标准曲线方程为y=(1.13302+1.75224)/[1+(x/1.08220)×(-0.60352)]-1.75224,R2=0.99908,线性范围为[0.05,30]ng/mL。该试剂盒可满足准确度相对偏差在±15%内、最低检测限≤0.05 ng/mL、特异度相对偏差在±15%内、批内差和批间差的变异系数均<15%的产品设计要求。稳定性检测结果标明该试剂盒可在2~30℃条件下有效保存12个月。同时,通过该试剂盒测得血清及血浆样本参考区间均<0.3 ng/mL。临床验证结果表明该试剂盒与罗氏Elecsys S100检测试剂盒的测定结果具有高度一致性(Kappa=0.9061>0.80),符合标准。结论:该试剂盒可快捷、准确、定量检测血清中S100B蛋白浓度,为神经类疾病、自身免疫病性疾病、脑血管疾病等的诊断与治疗提供了参考。

激光诱导钛合金等离子体电子温度和电子密度的时间分辨测量

以波长为532 nm的纳秒脉冲激光器为激发源,使用中阶梯光栅光谱仪和增强电荷耦合器件(ICCD)获得了激光诱导钛合金等离子体的时间分辨发射光谱;基于发射光谱,利用玻尔兹曼图法和萨哈-玻尔兹曼图法计算了等离子体电子温度;采用斯塔克展宽法计算了电子密度。研究结果表明,相较于玻尔兹曼图法,萨哈-玻尔兹曼图法可提供更为准确的电子温度计算结果。此外,光谱采集门宽的增大会导致等离子体电子温度和电子密度计算值的减小。以上研究结果为钛合金的激光诱导击穿光谱(LIBS)分析提供了实验指导。