包埋不同淡水耗氧菌BOD传感膜的光谱响应特征研究

利用四甲氧基硅烷(TMOS)、二甲基二甲氧基硅烷(DiMeDMOS)与聚乙烯醇(PVA)构成的有机改性材料分别包埋五种不同淡水耗氧菌,制备光化学生物耗氧量(BOD)的传感敏感膜,并在自行构建的BOD测定仪上考察其光谱响应行为.实验结果表明,分别包埋五种淡水耗氧菌和它们混合菌种的BOD传感膜对BOD的荧光强度响应范围为0～60 mg·L-1至0～120 mg·L-1,线性相关系数为0.976～0.997,响应时间为0.5～8.7 min,传感敏感膜可连续使用30 d以上.实验研究考察了不同实验条件下如温度和测定体系的pH对BOD传感膜响应的影响.实验结果发现,在4℃下保存12个月后,BOD传感膜仍保持原有响应值的85%以上,显示出较好的重复性和稳定性.初步应用结果表明,BOD传感膜可应用于地表水中的BOD检测.     

改进FIA荧光光度法测定维生素B_1含量

利用自行研制流动比色皿在荧光光度计上实现了流动注射荧光光度法检测口服药片(口服液)中VB1含量.荧光动态响应信号与维生素B1含量在0.025-3.20,μg·mL-1范围内呈良好线性关系(r=0.9996),检出限为0.025μg·mL-1对0.15μg·mL-1样品测定的相对标准偏差为1.43%(n=11).     

一种基于有机杂化溶胶-凝胶Hg2+敏感膜的研究

研究了基于有机杂化硅氧烷的Hg2 光化学传感膜,通过四甲氧基硅烷(TMOS)和二甲基二甲氧基硅烷(DMOS)进行缩聚,将5,10,15,20-四苯基卟啉磺酸钠与十六烷基三甲基溴化铵以离子对的形式包埋于溶胶-凝胶中,获得对Hg2 有灵敏荧光响应的溶胶-凝胶敏感膜.实验考察了传感膜的制备条件和响应性能.结果表明,在pH 8.0的Tris-HCl缓冲溶液中,Hg2 的浓度与传感膜的荧光猝灭比值在1.0×10-5～1.0×10-4mol·L-1范围内呈线性关系,传感膜具有响应时间短,指示剂不泄漏,测定重现性好,其他金属离子干扰小等优点.     

氧对钌(Ⅱ)配合物溶胶-凝胶膜荧光响应的影响

利用蓝光LED(λmax =4 6 0nm )构建的氧荧光猝灭检测系统 ,考察了不同Ru配合物以甲基硅氧烷(TMOS)和二甲基二甲氧基硅烷 (DiMe DMOS)为共先驱体 ,制备的有机改性溶胶 凝胶 (sol gel)膜内荧光猝灭行为。DiMe DMOS的加入量会影响敏感膜的极性 ,从而影响敏感膜对氧浓度的响应。利用自行构建的装置对水体中氧进行了检测 ,传感膜对氧饱和水溶液测定的相对标准偏差为 1 12 % (n =6 ) ,响应时间为 30s,对氮饱和水溶液测定相对标准偏差为 0 39% (n =6 ) ,响应时间为 90s,敏感膜使用寿命大于 6个月。     

BOD光化学传感敏感膜荧光响应的研究

利用自行构建的BOD光纤传感装置对海水中BOD含量进行了检测,考察了海洋耗氧菌种在四甲 基硅氧烷(TMOS)、二甲基二甲氧基硅烷(DiMe-DMOS)和聚乙烯醇(PVA)包埋情况下,对BOD的荧光响应 行为以及耗氧菌种的加入量对BOD浓度的响应情况。传感膜对5 mg·L-1 BOD溶液测定的相对标准偏差为 1.2％(n=6),响应时间为3．2 min,敏感膜使用寿命大于12个月。实际海水样品检测表明,利用BOD光纤 传感检测的结果与国标BOD5方法,存在较好的一致性。     

直接荧光法和流动注射荧光法测定微量氨的研究

在碱性介质中 ,基于氨与邻苯二甲醛及 2 巯基乙醇反应生成强荧光性吲哚取代衍生物的体系建立测定水溶液中微量氨的直接荧光法和流动注射荧光法。曲通X 10 0 (TritonX 10 0 )对该体系具有良好的增稳作用。在λex=4 15nm ,λem=4 86nm下 ,用直接荧光法测定NH3含量在 0 2～ 1 0 μg·mL- 1 范围内 ,工作曲线的回归方程为ΔI =2 2 2 86 785 71cNH3(μg·mL- 1 ) (I即为Intensity) ,r=0 9995 ;NH3含量在 0 0 2～ 0 10 μg·mL- 1 范围内 ,工作曲线的回归方程为ΔI=- 2 7 4 2 9 2 371 4cNH3(μg·mL- 1 ) ,r=0 996 5。用流动注射法测定的工作曲线的回归方程为ΔI=1188cNH3(μg·mL- 1 ) ,r=0 9998,线性范围为 0～ 0 7μg·mL- 1 ,并对反应机理进行初步探讨。     

新型水溶性花菁双嵌染料荧光测定蛋白质的研究

基于蛋白质对双嵌花菁染料具有良好的荧光增强作用,以新型水溶性碳菁染1,1'-丙磺酸-3,3,3',3'-四甲基吲哚三次甲基碳菁-5,5'-二磺酸钾为荧光探针,建立了一种新的蛋白质荧光检测体系.实验考察了探针的荧光特征、浓度、缓冲体系pH、盐浓度和乙醇有机试剂等参数对体系荧光的影响.当pH 2.0,花菁染料最大荧光激发波长为548 nm,发射波长为562 nm,血清蛋白与探针作用随着探针浓度的增加而加强,荧光增强值逐渐上升;当探针浓度为1.00×10-6 mol·L-1时,牛血清蛋白BSA和人血清蛋白HSA对花菁探针荧光增强作用最为明显,体系荧光强度与蛋白质浓度成良好的线性关系,BSA和HSA线性响应浓度范围分别为0.20～15.00 μg·mL-1和0.20～12.00 μg·mL-1,检测限(3σ/K)为0.01 μg·mL-1.测定了血清蛋白BSA的合成样品,当BSA浓度为4.00,6.00,8.00 μg·mL-1时,回收率为94.5%～103.3%.     

基于同步-导数荧光光谱法的多组分农药残留测定的研究

多组分农药残留物的荧光检测中,由于组分间结构与化学性质相似,导致荧光光谱相互重叠,常规荧光光谱法难以同时进行测量.利用同步-导数荧光光谱法对西维因与克百威这2种常用农药的荧光光谱进行了研究,并试验了pH值对两者荧光特性的影响.在pH为7.8的条件下,选择△λ=60 nm,在250～450nm的波长范围内对两者混合溶液进行了同步荧光光谱扫描,并做一阶导数处理.实验结果表明,两者的同步导数荧光光谱完全得到了分离,消除了彼此间的干扰,能够对两者的混合溶液进行同时测定.西维因与克百威的线性范围分别为0.013～1.156 μg·mL-1与0.025～1.042 μg·mL-1,检出限分别为0.013 μg·mL-1与0.025 μg·mL-1,回收率分别为98%～104%与96%～103%;相对标准偏差均低于2.25%.     

同步荧光光谱比率法检测过氧亚硝酸根及其清除剂的研究

利用同步荧光光谱建立了一种新的荧光比率法检测过氧亚硝酸根(ONOO-)及评价其清除剂的方法.酪氨酸自身有荧光,在pH 8.5的磷酸缓冲溶液中,酪氨酸与CO2和ONO-反应生成强荧光的酪氨酸二聚体,利用同步荧光光谱技术,在荧光发射光谱中能同时获得酪氨酸单体(λem=364 nm)与二聚体的荧光峰(λem=406 nm),且两峰的荧光强度的比值与ONOO-的浓度呈计量相关.结果表明荧光强度的比值不受实验参数改变的影响,与传统的荧光法相比,有利于扩大检测的线性范围,提高灵敏度.荧光强度的比值与ONOO-的浓度在1.60X10-7 mol·L-1～6.00X10-4 mol·L-1范围内呈线性关系,线性相关系数为0.999,检测限为1.84×10-8 mol·L-1.对浓度为1.00X10-6 mol·L-1 ONOO-平行测定8次,其相对标准偏差为2.4%.利用该法测得抗癌药米托蒽醌的ICso为0.065μg·mL-1.方法简便易行,试剂廉价易得,体系稳定,可作为一种检测ONOO-及筛选其清除剂的方法.     

吡咯红Y-过氧化氢-铬(Ⅵ)体系催化荧光法测定痕量铬(Ⅵ)

在HAc-NaAc缓冲体系中,痕量铬(Ⅵ)对过氧化氢氧化吡咯红Y的氧化还原反应有催化作用,使吡咯红Y荧光减弱,据此建立了催化荧光法测定痕量铬(Ⅵ)的新方法,同时考察了该催化反应的最优条件及动力学性质.该方法的表观活化能为159.92 kJ·mol-1,反应速率常量为5.7×10-2s-1,检测限为0.012μg·mL-1,测定线性范围为0.02～0.24 μg·mL-1.该方法用于对河水、工业废水及电镀废水中铬(Ⅵ)的测定,结果令人满意.     

纳米银与表面吸附荧光素的荧光性能的影响

研究了纳米银粒子对表面吸附荧光素(fluorescein,Fl)的荧光性能的影响.Fl溶液中加入纳米银粒子,Fl分子包覆在纳米银粒子表面形成Fln-Ag复合物使纳米银相互桥连形成类似网络的结构,且Fl分子吸收峰随着纳米银浓度的增加发生红移.纳米银通过产生的强局域场将能量传输给Fl发光中心,实现了Fl的荧光增强,荧光增强效率随着纳米银浓度的增加具有最大值.较大粒径的纳米银使Fl获得最大荧光增强效率所需浓度较低且最大荧光增强效率值较高.研究结果表明,纳米银与Fl间的能量传输主要由Fl分子附近局域电磁场增强和分子到金属表面无辐射跃迁能量转移过程所决定并与纳米银的浓度、尺寸密切相关.     

基于钌配合物荧光猝灭氧二次传感BOD检测的研究

考察了利用溶胶-凝胶基质制备的氧荧光传感膜的光谱性质,实验结果表明,溶胶-凝胶基质与Ru(dpp)3(ClO4)2配合物的基态之间不存在较强的相互作用,具有较好的透光性.将氧光化学传感器作为二次传感,制备了响应良好的光化学BOD微生物传感器,研究结果表明这种传感器对于较低浓度的BOD含量有着良好的线性范围,并且其响应活性保持良好,具有较长的使用寿命和良好的稳定性.     

A highly flexible polymerization technique to prepare fluorescent nanospheres for trace ammonia detection

The preparation of pH-sensitive nanospheres by emulsion polymerization for the detection of trace levels of ammonia is described. A fluorescent, polymerizable xanthene dye was copolymerized with styrene, crosslinkers and further copolymers aimed at enhancing the sensitivity to obtain materials for sensing of ammonia. A half-seeded technique was used to obtain stable emulsions of the monomers which were cured to obtain nanospheres with covalently attached active components. The nanospheres were embedded in a silicon matrix and the sensor films obtained were investigated regarding their response to ammonia at concentrations between 25 and 1,000 ppb. Sensors containing polystyrene nanospheres crosslinked with divinylbenzene showed the best performance in ammonia measurements exhibiting detection limits (LODs) of less than 25 ppb ammonia.     

8—羟基喹啉铝的荧光老化机制

报导了８－羟基喹啉铝（Ａｌｑ３）在紫外光照射下发生荧光猝灭的机制,测量了Ａｌｑ３在光照射前后的紫外－可见吸收光谱、荧光光谱、红外吸收光电子能谱（ＸＰＳ）,分析了紫外光照射后Ａｌｑ３分子结构变化,证明了产生结构变化的根源是中水与Ａｌｑ３发生了化学反应,对Ａｌｑ３的我老化机制提出了可能的解释。     

Silver nanocrystals modified microstructured polymer optical fibres for chemical and optical sensing

In-fibre chemical and optical sensors based on silver nanocrystals modified microstructured polymer optical fibres (MPOFs) were demonstrated. The silver nanocrystals modified MPOFs were formed by direct chemical reduction of silver ammonia complex ions on the templates of array holes in the microstructure polymer optical fibres. The nanotube-like and nanoisland-like Ag-modified MPOFs could be obtained by adjusting the conditions of Ag-formation in the air holes of MPOFs. SEM images showed that the higher concentration of the reaction solution (silver ammonia 0.5 mol/L, glucose 0.25 mol/L), gave rise to a tubular silver layer in MPOF, while the lower concentration (silver ammonia 0.1 M, glucose 0.05 M) produced an island-like Ag nanocrystal modified MPOF. The tubular Ag-MPOF composite fibre was conductive and could be directly used as array electrodes in electrochemical analyses. It displayed high electrochemical activity on sensing nitrate or nitrite ions. The enhanced fluorescence of dye molecules was observed when the island-like Ag-modified MPOF was inserted into a fluorescent dye solution.     

Optical-gain enhancement of carbosilane dendrimer containing fluorescein groups in the periphery

In this article, a carbosilane dendrimer functionalized in the periphery with fluorescein units was prepared, and the optical property of the fluorescent dendrimer as gain medium was investigated. It was found that the dendrimer consisted of a methylphenylsilane core with 16 fluorescein units in its periphery. The dendrimer exhibits high optical-gain enhancement in methanol solution and laser emission was observed, which is located at 527 nm above the lasing threshold of 0.9 mJ/pulse.     

氮气/氨气的高压快脉冲放电光谱研究

本文测量了氮气、氨气及其混合气体的快脉冲放电等离子体的光谱,用光谱分析方法研究了等离子体成分及其与气压和配比的关系,并讨论了在制备氮化物时使用氮、氨混合气体的有利之处。     

Efficient Fluorescent Recognition of Carboxylates in Aqueous Media Using Facilely Electrosynthesized Poly(9-Aminofluorene)

A variety of carboxylates were recognized using poly(9-aminofluorene) (P9AF) in the HEPES buffer (pH 7.4), and a proposed possible mechanism was proposed as following. The intermolecular hydrogen bonding interactions resulted in electron transfer between P9AF and carboxylates. P9AF was facilely electrosynthesized in boron trifluoride diethyl etherate and could be used as an efficient fluorescent sensing material for the detection of AcO^?. On binding to AcO^?, fluorescence quenching of P9AF was demonstrated by a maximum 80 % reduction in the fluorescence intensity, while no obvious fluorescence change could be observed in the presence of some other common anions. Some different carboxylates could be recognized at different levels by P9AF. Substituent groups in carboxylates could affect the intermolecular interaction between carboxylates and P9AF. These could be explained by a possible mechanism that hydrogen bonding was the main way of intermolecular interactions between P9AF and carboxylates, which was further confirmed by absorption spectra monitoring and density functional calculations. The significant advantage of this strategy is that it does not require a prequenching procedure and the polymer can be used directly for analyte detection.