Determination of Chondroitin Sulfate with High Sensitivity by Fluorescence Recovery through Shifting the Equilibrium between Anionic Phthalocyanine and Cationic Surfactant

目的建立高灵敏荧光增强法测定硫酸软骨素的新方法,并用于实际样品测定。方法对荧光光谱行为的考察显示,在PH 7.0的介质中,具有共轭结构的阳离子头部和长碳链尾部的阳离子表面活性剂对四磺基铝酞菁(AlS4PC)的荧光具有高效猝灭作用,二者形成无荧光离子缔合物。此离子缔合物可对带有磺酸基团的高分子黏多糖硫酸软骨素(CS)作出灵敏响应。在CS的存在下,反应体系荧光显著恢复,最大恢复倍数可达900倍。由于猝灭效率高,荧光恢复程度大,甚至可实现目视化观测。结果工作曲线响应区间0.2~6μg·Ml-1,检测限0.09μg·Ml-1,工作曲线lOgy=0.158 23ρ-0.035 97,r=0.998 7。本实验对该法用于批量样品分析的可行性进行了考察,结果表明,所建立的方法可望用于高通量分析。结论该法操作简便,灵敏度、稳定性与检测准确性好。所建立的方法成功地用于组成复杂的实际样品中CS的定量分析,解决了实际工作中的难点。OBJECTIVE To propose a novel method for quantitative determination of chondroitin sulfate in real samples using the ion-association phthalocyanine complex as a fluorescent probe emitting at red-region.METHODS The fluorescence of tetrasulpnonated aluminum phthalocyanine( AlS4Pc),an anionic metal phthalocyanine,was quenched dramatically by cationic surfactants which contain a positively-charged head with a conjugated structure and a long carbon chain as tail through the formation of an almost non-fluorescent association complex.Hexadecylpyridinium bromide( CPB) screened from a series of cationic surfactants was selected as a quencher because of its high fluorescence quenching efficiency.It was found that the ion-association complex( AlS4Pc-CPB) emitted strong fluorescence in the presence of chondroitin sulfate,due to the ability of chondroitin sulfate to shift the association equilibrium of the ionassociation complex,which led to the release of AlS4Pc,thus resulting in an increase in the fluorescence of AlS4Pc.The method based on the above-mentioned phenomenon was investigated in the aspects of spectral characteristics,effect of pH,influence of reaction time, order of addition of reagents,the usage of reagents,and interference of foreign substances.RESULTS Under optimal conditions,the linear range of the assay for chondroitin sulfate was 0.2- 6 μg·mL- 1with a detection limit of 0.09 μg·mL- 1.CONCLUSOIN The established method is not only sensitive,accurate but also simple and reliable.It has been used to the analysis of real samples with complicated composition with satisfactory results.It has also been successfully applied in batch test combined with well-reader technique,exhibiting great potential for high-throughput analysis.福建省科技重点资助项目(2012Y0081); 福建省公益类科研院所基本专项(2010R1101)资助项

Trends of the International Plant Root Exudates Studies based on Bibliometrical Analysis

近几十年来,根系分泌物及其在生态学中的应用研究取得了很大的进展,植物根系分泌物尤其是森林植被的根系分泌物在生态恢复重建过程中的作用和功能受到越来越多的重视。本文以SCIE、CPCIS、CR、IC等数据库为统计分析源,检索并分析了数据库中关于根系分泌物的研究论文(论文、会议论文和综述)产出,利用Thomson Data Analyzer (TDA)分析工具和Aureka分析平台进行数据挖掘。分析表明,该研究涉及多个学科领域,近年来在植物与土壤等学科领域的论文数量最多,而在国家分布的主题领域,美国在该领域的论文产出量最高,为全部论文产出的28.93%,基金资助情况方面,以美国国家科学基金会、中国国家基金委为植物根系分泌物研究的主要资助机构。另外从主题词分布、年度研究主题变化等文献计量学的角度进行了统计分析,以揭示国际国内关于植物尤其是林木(区别于作物)根系分泌物研究的发展现状和态势