应用荧光光谱法检测蓝藻生物量

本研究应用荧光分光光度计,通过对水华鱼腥藻活体荧光光谱的扫描,确定了蓝藻藻蓝蛋白荧光测定的最佳荧光激发波长为620nm,荧光发射波长为650nm,建立了水华鱼腥生物量与藻蓝蛋白特征荧光强度的线性检测关系,表明应用荧光光谱法检测藻蓝蛋白荧光强度反应蓝藻生物量具有特异性和可行性,该方法具有简便、快速、操作简单、样品无需处理等优点。为测定蓝藻生物量提供了新的检测方法。     

多功能灵敏固相时间分辨荧光免疫分析仪设计

针对固相时间分辨荧光光谱的测量,设计出一种全新的固相时间分辨荧光免疫分析系统.使用氮分子激光器作为激发光源,采用积分球和单色仪相结合的荧光收集结构,使杂散光对样品荧光的影响降到最低;用光电倍增管进行光电转换,在500～700 nm范围实现了高分辨荧光光谱测量;利用数字方式实现取样积分功能,提高了系统的信噪比.系统可实现荧光寿命、时间分辨荧光光谱、物质浓度的自动测量,仪器的检测灵敏度可达10 - 12 moL/L,线性范围为10-12～10-9 mol/L,稳定性相对误差小于3％,荧光光谱分辨为0.5nm.     

基于激光诱导荧光技术的蒽检测系统

介绍了一种用Nd：YAG的三倍频（波长355nm）作为激发光,CCD作为探测单元,加上其他光学元件构成的激光诱导荧光检测系统,并测量了蒽的乙醇溶液的荧光光谱。分析了荧光强度与蒽溶液浓度的关系。实验结果表明,蒽溶液浓度在0．003～0．700mg／L范围内与荧光强度有良好的线性关系,相关系数为0．9987,检出限为1．3ng／mL,蒽的回收率在98％～106％范围内。系统适合用于蒽的激光诱导荧光检测。     

CCD多道光谱检测系统的研制

CCD器件是一种发展十分迅速的阵列式光电器件.本文介绍一种微机控制的CCD多道光谱接收系统.该系统光谱工作范围为0.4～1.1μm.在光谱仪线色散率为0.8nm/mm的条件下,能分开的最小波长差为0.02nm.一次谱图接收范围为21nm.介绍了系统的硬件、软件及实验结果.     

适于土壤中农药检测的荧光光纤系统

提出了一种用于土壤中农药检测的光纤式荧光测量系统.研究了有机物分子发荧光的基本原理,分析了荧光法检测农药的可行性.基于光纤传感技术和荧光技术设计了测量系统,系统以脉冲氙灯为激发光源,以特制的光纤式锥形探头探测荧光,以小型平场光谱仪实现荧光分光,以高速数据采集模块实现荧光信号的采集转换.该系统一次曝光即可获得农药的荧光光谱.利用该系统实现了不同浓度西维因在土壤中的荧光光谱实验,考察了系统的工作曲线和最低检出限.实验结果表明,系统测得的荧光光谱清晰、分辨率高;在0.005～0.1 mg/kg范围内荧光强度和浓度基本呈线性关系;系统的最低检出限(LOD)可达0.005 mg/kg ,相对标准偏差(RSD)≤3%,能够满足土壤中农药检测的需要.     

国产绝对荧光量子产率测量系统的研制

为实现物质荧光量子产率的绝对法测量,研制了一套绝对荧光量子产率测量系统。系统主机采用国产荧光分光光度计,激发和发射波长范围均为200～900 nm。光路设计采用积分球技术,保证了样品的散射和发射光线被充分收集,具备进行绝对法荧光量子产率计算的基础。光谱校正采用罗丹明B量子计数器和标准钨灯相结合的方式,确保测量结果的准确性。研制的荧光量子产率分析软件具备自动光谱校正和自动计算量子产率功能。测试结果表明,系统的测量准确性较高,可满足大部分荧光物质的测试要求。     

多波长激发高分辨率微型拉曼光谱仪设计

针对不同激光波长激发测试样品所需拉曼光谱范围的差异性问题,同时为了保证拉曼光谱仪的小型化及高分辨率需求,提出一种以Czerny-Turner光路结构为基础的微型拉曼光谱仪,通过Zemax光学设计软件对光谱仪的准直镜、聚焦镜、柱面镜、光栅以及CCD的倾角及距离进行了优化。该仪器激光波长为633 nm,光谱范围为640～800 nm。进一步优化光栅旋转角度并配合聚焦镜,可使此光学系统同时适用于激光波长532 nm、光谱范围540～650 nm和激光波长785 nm、光谱范围790～1 000 nm两个波段。拉曼光谱仪分辨率为0.1 nm,该光谱仪在保证高分辨率的情况下解决了不同波段范围光学结构差异性大而导致光机设计很难整合在一起的问题。     

基于激光二极管的近红外水分仪研制

本研究开发一种基于近红外光谱技术,采用两只激光二极管(LD)光源,其中1490nm为水分的特征吸收波长,1310nm作为参考波长,使用积分球作为载样器件和使用LabVIEW虚拟仪器程序开发语言编写系统程序的新型近红外水分仪。该仪器去除一般光谱仪器中的分光部件,从而有利于提高系统的稳定性和信噪比。经茶叶和奶粉的实测试验证明,该仪器的检测精度较高,基本能满足实际生产中对水分检测的需要。     

三维荧光光谱检测地沟油

利用三维荧光光谱检测灵敏度高、选择性强和快速无污染的优点,对掺入了不同比例地沟油的植物油进行了检测。实验结果表明,当掺入的地沟油的含量超过10%时,根据三维荧光光谱的荧光图案特征和特定荧光激发波长的荧光强度下降程度,可以作为判断该植物油是否掺入了地沟油的依据。使用三维荧光光谱检测地沟油优于其他检测方法,其灵敏度和快速、实时的特点适合用于地沟油的测定。     

细胞内钙离子浓度检测关键技术

研究并设计了用于活体单细胞内钙离子浓度定量检测的微流控荧光检测系统。首先用微流控芯片完成细胞的培养、染色、驱动和定位等操作,接着分别用波长为340 nm和380 nm的单色光去激发染色后的细胞使之发出荧光,并用光电倍增管(PMT)和电荷耦合器件(CCD)采集荧光强度和荧光图像,最后利用荧光比值法计算出细胞内钙离子的浓度。同时,使用该系统记录了高K~+刺激下细胞内钙离子浓度的变化。结果表明此系统稳定可靠,测量数据准确,满足生理学研究中检测活体细胞内钙离子浓度的需要。     

激光扫描共聚焦光谱系统设计

为提高激光扫描共聚焦显微镜光谱模块的分光性能,设计了双Amici棱镜光谱结构.根据棱镜色散特性,计算得到Amici棱镜和双Amici棱镜的线性与非线性数学模型,给出直视型棱镜结构参数.比较相同色散条件下Amici和双Amici棱镜结构,得到双Amici棱镜组能提供更好的色散线性度.在光谱波段400～700 nm,中心波...     

Autofluorescence spectroscopy and imaging of Platymonas subcordiformis irradiated by diode laser based on LSCM

Autofluorescence spectra and optical imaging of Platymonas subcordiformis after irradiation of diode laser were observed via laser scanning confocal microscopy (LSCM). With 488 nm Ar(+) laser excitation, the horizontal and vertical dimensions of a cup-shaped chloroplast of the irradiation group increased about 10% compared with the control group. The fluorescence spectra were similar between irradiation group and control group with a maximum fluorescence band around 682 nm, whereas the former has a higher intensity. Image of a small circular substance with stronger two-photon autofluorescence (TPA) was obtained when using two-photon excitation wavelength of 800 nm in single-channel mode. Further analysis by the 800 nm excitation based on two independent-channels mode showed an emission band of the small circular substance around 376-505 nm, which corresponded to the eyespot of P. subcordiformis. In lambda scanning mode, with two-photon wavelength of 800 nm excitation, six fluorescence peaks that are located at 465, 520, 560, 617, 660 and 680 nm were observed; the fluorescence intensity of the irradiation group was higher than that of the control group, especially at 520, 560 and 617 nm. As a conclusion, diode laser irradiation can promote chloroplast growth of P. subcordiformis cells in the form of expanding area and the increasing content of protein, phospholipids and chlorophyll. LSCM, especially TPA imaging based on femtosecond laser excitation, provides a nondestructive, real-time and accurate method to study changes of living algal cells under laser irradiation and other environmental factors.     

Xenon ion laser-induced fluorescence using a visible tunable diode laser near 680 nm

Laser-induced fluorescence (LIF) measurements have been performed for the first time in a low temperature (Te approximately 0.6 eV) Xe plasma using a tunable diode laser in the visible range of wavelengths. The transition in Xe II involved the (3P1)5d[3]7/2 metastable state and the excitation wavelength was found to be 680.570+/-0.001 nm (air). LIF measurements of I 2 in a room temperature iodine gas cell were used to monitor the wavelength of the laser during the measurements.     

Controlled Synthesis and Optical Properties of Pure Gold Nanoparticles

Abstract

Gold nanoparticles were synthesized by laser ablation of a gold metallic disc at wavelengths of 532 nm and 355 nm with 7 ns pulse duration in the pure water. The colloidal gold nanoparticles were characterized by ultraviolet-visible absorption spectroscopy, transmission electron microscopy, and fluorescence spectrometry. The presence of a surface plasmon resonance peak around ～ 524 nm indicates the formation of gold nanoparticles. The formation efficiencies of gold nanoparticles in colloids were found to increase when ablating the gold metallic disc with a laser having a longer wavelength. The size distributions of the gold nanoparticles thus produced were measured by transmission electron microscopy. A reduction in mean diameter of the particles was observed with a decrease in the laser wavelength under the irradiation at a high fluence of 25 mJ/pulse. The fluorescence spectroscopy demonstrated that these gold nanoparticles are fluorescent, showing a strong blue emission intensity at 458 nm.     

Determination of total polyphenols in tea by a flow injection-fiber optic spectrophotometric system

A flow injection-fiber optic spectrophotometric system was established for the online determination of total polyphenol content in tea samples. The method was based on the chromogenic reaction between the phenolic compounds (gallic acid) and ferrous tartrate which was used as the colorimetric reagent and the absorption was determined at the maximum absorption wavelength of 540?nm at 20°C and pH 7.5. The calibration curve from standard solutions of gallic acid was linear in the range from 0.010 to 0.100?mg/mL with a correlation coefficient of 0.9970. The relative standard deviation of polyphenol measurements for eight tea samples was between 0.55 and 3.18%. It can be concluded that the proposed method has allowed simple, fast, and accurate determination of total polyphenol content in tea products.     

Fluorescence reactions of orcein: new applications for an old stain

The fluorescence properties of orcein are described in this paper. Under suitable exciting light, acidic solutions of orcein showed emission peaks at 587 nm (low concentration) and at 620 nm (high concentration). In fluorescence microscopy an intense orange-red emission was found in the cytoplasm and nucleoli from acetic orcein squashes of meristematic cells, as well as in the cytoplasm of Ehrlich tumour cells and in chicken erythrocyte nuclei. When semithin sections of Epon-embedded tissues were treated with orcein, a strong fluorescence reaction (orange-red) appeared in starch granules, cell walls, elastin, collagen, reticulin, keratohyalin, chromatin and mucin. Cytofluorometric measurements of orcein-stained chromatin revealed an emission peak at 585 nm with a shoulder at 620 nm. These spectroscopic and microscopical results suggest the possibility of employing orcein as a fluorochrome.     

Determination of benzotriazole in industrial cooling water by fluorescence

Benzotriazole is widely used in various industries to inhibit corrosion. Sensitive instruments and methods are needed to determine this compound in industrial cooling water. Fluorescence spectroscopy was used to determine benzotriazole in this application. The optimum wavelength was evaluated as well as the influence of pH, temperature, and common ions. Ultraviolet-visible absorption spectroscopy showed that there were two peaks: 259?nm and 278?nm. The latter wavelength was shown to be optimum for the determination of benzotriazole. The fluorescence intensity was linear with concentration from 0.4–4?mg/L. The pH, temperature, and presence of other ions had little effect on the analysis. The detection limit was 0.155?mg/L. In summary, fluorescence spectroscopy was demonstrated to be convenient, sensitive, and economical for the determination of benzotriazole in industrial cooling water.     

真空紫外辐照对Lumogen薄膜损伤及光学性能的影响

为研究Lumogen(C₂₂H₁₆N₂O₆)薄膜在真空紫外波段的光致发光特性及辐照损伤,采用热阻蒸发法,以氟化镁为基底制备Lumogen薄膜。使用真空紫外荧光光谱仪、原子力显微镜(AFM)、扫描电子显微镜(SEM)、紫外?可见分光光度计等仪器分别对薄膜的光致发光特性、荧光强度衰减变化、表面形貌、透过率等进行测试与表征。实验结果表明,真空紫外波段的最佳激发波长为160 nm;发射峰宽为500~620 nm,峰值位置是在528 nm处;在160 nm激发波长持续辐照20 h后,发射峰位置的荧光强度由快及慢地从8.76衰减为0.83,整体下降了90.5%;薄膜表面的均方根粗糙度从10.96 nm增加到14.96 nm;160 nm真空紫外光的高光子能量使Lumogen分子中的荧光助色团-OH断裂,薄膜表面受损,造成不可逆的破坏;被真空紫外光持续辐照后的Lumogen薄膜在250~450 nm波段内的透过率下降了约50%。研究结果表明,Lumogen薄膜在持续高能真空紫外光辐照下,薄膜表面会造成损伤,光学性能会下降,为其在紫外探测器件及航空航天领域的应用研究提供一定参考。