Magnetically assisted fluorescence ratiometric assays for adenosine deaminase using water-soluble conjugated polymers

A magnetically assisted fluorescence ratiometric technique has been developed for adenosine deaminase assays with high sensitivity using water-soluble cationic conjugated polymers (CCPs). The assay contains three elements: a biotin-labeled aptamer of adenosine (biotin-aptamer), a signaling probe single-stranded DNA-tagged fluorescein at terminus (ssDNA-Fl) and a CCP. The specific binding of adenosine to biotin-aptamer makes biotin-aptamer and ssDNA-Fl unhybridized, and the ssDNA-Fl is washed out after streptavidin-coated magnetic beads are added and separated from the assay solution under magnetic field. In this case, after the addition of CCP to the magnetic beads solution, the fluorescence resonance energy transfer (FRET) from CCP to fluorescein is inefficient. Upon adding adenosine deaminase, the adenosine is converted into inosine, and the biotin-aptamer is hybridized with ssDNA-Fl to form doubled stranded DNA (biotin-dsDNA-Fl). The ssDNA-Fl is attached to the magnetic beads at the separation step, and the addition of CCP to the magnetic beads solution leads to efficient FRET from CCP to fluorescein. Thus the adenosine deaminase activity can be monitored by fluorescence spectra in view of the intensity decrease of CCP emission or the increase of fluorescein emission in aqueous solutions. The assay integrates surface-functionalized magnetic particles with significant amplification of detection signal of water-soluble cationic conjugated polymers. Supported by the “100 Talents” Program of the Chinese Academy of Sciences, and the National Natural Science Foundation of China (Grant No. 20574073)     

水溶性荧光聚合物的制备与性能分析

基于Wittig-Horner反应, 以对氯甲基苯甲酸甲酯、亚磷酸三乙酯、对苯二甲醛为主要原料, 经酯化、缩合得到二苯乙烯型荧光单体, 研究了各种反应条件对单体合成的影响. 将二苯乙烯型荧光单体高分子化得到了水溶性好、荧光性强、稳定性与安全性高的荧光聚合物. 用红外光谱对荧光单体结构进行了表征, 用紫外及荧光分光光度计对荧光单体及聚合物的荧光性能进行了研究. 结果表明: 荧光单体聚合后紫外吸收发生红移, 吸收强度下降, 但荧光发射强度提高, 这说明近紫外吸收有利于荧光发射强度的提高.     

Synthesis and photocurrent response of porphyrin-containing conjugated polymers

In recent years conjugated polymers have attracted considerable attention because of their potential appli- cations in the fields of light emitting diodes, photo- voltaic devices, and sensors[1―7]. In the fabrication of semiconductor photovoltaic devices…     

氟硼二吡咯类共轭聚合物均相检测miRNA研究

基于水溶性氟硼二吡咯类共轭聚合物PBF可与长波长区(> 600 nm)荧光染料产生荧光共振能量转移(FRET),结合引物延伸反应,发展了一种均相检测miRNA的新方法.方法首先通过引物延伸反应在目标miRNA分子上引入荧光染料Cy5,形成miRNA-Cy5. 然后,PBF与miRNA-Cy5/DNA杂合体通过静电力结合并发生从PBF到Cy5的有效FRET,实现了基于阳离子共轭聚合物(CCP)的长波长区miRNA的均相检测,方法灵敏度高、特异性好,测定miR-221的线性为15~6 000 pmol/L,检出限(3σ)为8.4 pmol/L.方法拓展了CCP的应用,为基于CCP的生物传感和生化分析提供了新的均相检测平台.     

Synthesis and photophysical properties of linear and hyperbranched conjugated polymer

A novel light-emitting alternating copolymer, known as hyperbranched conjugated polymer (HPV), has been designed and synthesized by Wittig reaction, and so have its linear counterparts, including MPV and PPV. FTIR, 1H NMR, 13C NMR and GPC were combined to characterize these polymers. Their photophysical properties were investigated both in solution and in solid film. Interestingly, almost the same maxima of absorption and emission wavelengths were observed for the solution of HPV and MPV in CH2Cl2 respectively, located at the shorter wavelength region related to PPV. In addition, the absorption peak of HPV film blue shifted while its emission peak red shifted as MPV compared with the case of its CH2Cl2 solution. However, both the absorption and emission spectra of the PPV film showed red shift, which resulted from a special electronic structure.     

Synthesis, conductivity and photosensitivity of 2-D conjugated polymers of metalporphyrazine with sulfur bridges

The title polymers PMS₈Pz, M=Mn^II, Fe^II, Co^II, Ni^II, Cu^II, Zn^II, were synthesized by reaction of 2, 3, 5, 6-tetracyano-1, 4-dithiin with corresponding metal salts, respectively. The structure and properties of these polymers were characterized by elemental analysis, transmission electron microscope, DTA, IR, UV-Vis, fluorescence and EPR spectra. It has been found that these conjugated polymers have the property of intrinsic semiconductor. The conductivity σ_298K of these polymers is in the range of 10⁻⁹≈10⁻³ S·cm⁻¹ under pressure 10.63 MPa and incrementals in the metal order Mn<Co<Fe<Zn<Cu<Ni. The photosensitivity of the MS₈Pz to the CdS-PVA films is incrementals in the metal order Zn<Mn<Co<Fe<Cu<Ni. Supported by the National Natural Science Foundation of China and by the Approach Fund of State Key Laboratory of Coordination Chemistry in Nanjing University Peng Zhenghe: born in Apr. 22, 1945, Professor     

微孔共轭聚合物的合成调控及其吸附研究进展

微孔共轭聚合物(CMPs)具有高比表面积以及高孔隙率等性质,是一类重要的吸附材料。本文综述了CMPs材料的合成、调控及其在吸附领域应用的研究现状,归纳总结了不同偶联方式制备的CMPs所具有的不同特点,讨论了反应单体的结构和比例以及反应溶剂、反应温度、催化剂用量和反应添加物等参数对CMPs的分子结构、形貌和孔道孔隙的影响规律,明确了制备CMPs适宜的调控策略。同时介绍了CMPs在重金属和有机物等污染物吸附上的应用,并对CMPs未来研究方向进行了展望。     

Charge carrier photogeneration in conjugated polymer PhPPV/R6G composite system

Photoconducting organic materials including conju-gated polymers[1―3], organic molecules[4,5], stacked disco- stic liquid crystals[6,7] and self-assembling organic semi-conductors[8,9] have attracted intense interests due to their extraordinary performances. Their charge carrier photo-generation mechanism has been one of the most important subjects of large amounts of publications in view of possi-ble applications in electronic devices such as photovoltaic cells[10―19]. The charge carrier ph…     

Integration of rolling circle amplification and cationic conjugated polymer for the homogeneous detection of single nucleotide polymorphisms

A novel, homogeneous and sensitive assay for the detection of single nucleotide polymorphisms (SNPs) by integration of rolling circle amplification (RCA) and cationic conjugated polymer (CCP) has been developed and tested. Mutant DNA serves as the template for specifically circularizing a padlock probe (PLP) with a sequence that is complementary to the mutant DNA. Afterwards, the mutant DNA directly acts as the primer to initiate the RCA reaction in the presence of phi29 DNA polymerase that generates a long, tandem single-strand DNA product. During the RCA reaction, fluorescein-labeled dUTPs are incorporated into the RCA products. When the CCP is introduced, efficient FRET from CCP to fluorescein occurs as a result of the strong electrostatic interactions between the CCP and the DNA produced by RCA. The wild-type DNA contains a single base mismatch with PLP with the result that the PLP is not circularized, RCA is not triggered and inefficient FRET results. By measuring the change of the emission intensities of CCP and fluorescein, it was possible to detect the SNP in a homogeneous manner. The method is sensitive and specific enough to detect 0.1 pmol/L mutant DNA and to determine a mutant allele frequency as low as 2.0%.     

Plasmonic biosensors and nanoprobes based on gold nanoshells

Gold nanoshells (GNSs), consisting of a dielectric core coated with gold, have gained extensive attention as they show readily tunable optical properties and good biocompatibility. As highly sensitive and label-free optical biosensors with wide applications, GNSs have been investigated in many fields including drug delivery, immunoassay, cancer treatment, biological sensing and imaging. Taking advantage of the adjustability of the local surface plasmon resonance (LSPR) and the sensitivity of the surfaceenhanced Raman scattering (SERS) signal of GNSs, we have developed diverse applications including plasmonic biosensors and nanoprobes based on GNSs. In this review we introduce plasmonic and electromagnetic properties and fabrication methods of GNSs. We describe research progress in recent years, and highlight several applications of GNSs developed by our group. Finally we provide a brief assessment of future development of GNSs as plasmonic materials that can be integrated with complementary analytical techniques.     

Highly stretchable and sensitive strain sensor based on silver nanowires/carbon nanotubes on hair band for human motion detection

In this work, a highly stretchable and sensitive strain sensor using silver nanowires(Ag NWs)/multi-walled carbon nanotubes(MWCNTs) on hair band is proposed. The fabrication process of such sensors enabled scalable and facile production with low cost by dipping hair band into Ag NWs/MWCNTs composites suspension. The sensing performance of the sensors was optimized by tuning the Ag NWs/MWCNTs mass ratio. The hair band based strain sensor with Ag NWs/MWCNTs mass ratio of 30 exhibited the best perf...     

基于共轭FRFT模函数对消的运动目标检测

分析了回波信号以及其共轭信号的FRFT幅值特性,并利用此特性提出了一种基于共轭FRFT模函数对消的海面运动目标检测方法。该方法利用回波信号在最佳变换角度有较好的能量聚集,而其共轭信号在此最佳变换角度没有能量聚集。利用两者FRFT模函数之差对消部分杂波,在保证信号能量基本不被削弱的前提下达到抑制杂波、提高检测概率的目的。高斯噪声与IPIX雷达数据实验表明该方法在低信杂比条件下有较好的检测性能。     

基于还原氧化石墨烯/普鲁士蓝-壳聚糖纳米复合物的高灵敏葡萄糖生物传感器研究

在电沉积制备普鲁士蓝-壳聚糖(PB-CS)膜修饰金电极的基础上,引入新型纳米材料还原氧化石墨烯(RGO),固定葡萄糖氧化酶(GOD),构建基于RGO/PB-CS纳米复合材料的葡萄糖生物传感器。结果表明,由于RGO独特的物理化学性质以及RGO与PB之间的协同作用,大大提高了此传感器的工作性能。在0.0V工作电位下,该传感器具有较高的灵敏度(65.3μA·(mmol/L)-1·cm-2)和较低的检测限(6μmol/L)。传感器具有较小的表观米氏常数(1.43mmol/L),表明该固定酶对葡萄糖具有较高的亲和力。     

基于相位检测SPR生物传感器的数值模拟

为了得到基于相位检测的表面等离子体共振(SPR)生物传感器的高检测精度,建立了这种传感器的5层膜结构的数学模型,利用Matlab系统地进行了耦联层、传感层等对所检测相位变化影响的数值模拟,确定了一组优化参数。模拟结果表明,相位检测对传感层的折射率具有选择性。获得较高的分辨率的条件是:耦联层厚度应小于150nm,优选值是50nm;不生成传感亚层时,传感基层的厚度应控制在200nm左右;当生成传感亚层时,传感层(包括基层和亚层)的总体厚度须根据反应物分子的特异性系统考虑。     

阴离子表面活性剂化学传感器聚合物敏感膜的研制

对阴离子表面活性剂化学传感器敏感膜的种类组成及其比例进行了筛选,确定了增塑剂为磷酸三甲酚酯,其质量分数为55%~75%;电活性物质为十六烷基三甲基溴化铵,其质量分数为0.6%~1%;聚合物基体为聚氯乙烯(PVC),其质量分数为24%~44.4%。实验结果表明,敏感膜机械强度好,其对阴离子表面活性剂的线性响应范围为1×10-7~1×10-3mol/L,阴离子表面活性剂浓度为1×10-3mol/L时,其响应时间为30 s。     

Highly sensitive detection of melamine based on reversed phase liquid chromatography mass spectrometry

In this work, we developed a highly sensitive method to detect melamine based on reversed phase liquid chromatography mass spectrometry. A mass spectrometry compatible ion pair, heptafluorobutyric acid(HFBA), was used to separate melamine by reversed phase liquid chromatography prior to electrospray mass spectrometry. The incorporation of isotope internal standard and multiple reaction monitoring improved the accuracy and linearity of quantification. Based on this strategy, the method limit of quantification was 0.1 ng/g. The limits of quantification were 8 ng/g for liquid milk and 15 ng/g for dry milk powder. This method provided a reproducible and stable approach to sensitive detection and quantification of melamine. Supported by the National Natural Science Foundation of China (Grant No. 30425021) and National High Technology Research and Development Program of China (Grant No. 2007AA02Z334)     

基于氟硼二吡咯的水溶性高灵敏汞离子荧光探针

以氟硼二吡咯作为荧光基团、以肼基作为活性基团设计、合成了一种可用于物质的量高灵敏地检测水溶液中汞离子的荧光探针(MS).该探针在水溶液中5 min内基本可以完成对汞离子的检测,随着汞离子浓度的增加,溶液紫外吸收明显红移,荧光强度大大增强.即使体系中汞离子物质的量浓度在0.1μmol/L时,溶液荧光强度也有明显变化,说明该探针具有很高的灵敏度.另外选择性实验表明该探针在相同条件下对其他常见金属离子没有明显响应,说明该探针具有很好的选择性.     

基于地磁传感器的车辆检测算法*

地磁传感器是一种利用地磁变化来检测车辆的新型设备。通过分析大量地磁数据,提出一种基于波形峰谷值特征的车辆检测算法。该算法可以自动跟踪基线值并提取车辆信号特征。实际道路检测试验数据表明该算法简单有效,准确率可达98.5%以上。该系统可以应用于道路车流量检测,平均车速统计等,将在智能交通领域发挥重要作用。     

基于氧敏感膜的海水溶解氧测定技术研究

提出了一种利用荧光猝灭原理测定海水溶解氧的方法,分别从光电检测电路、LED驱动电路、光电二极管电路、温度检测电路、信号产生采集处理控制电路等方面详细介绍了基于氧敏感膜的海水荧光信号检测系统设计方案,通过实验测试了荧光信号检测系统对荧光相位滞后检测能力、系统的整体稳定性和系统测试数据的准确度。准确度测试中溶解氧测试数据点饱和度从100.00%减小到11.56%,氧敏感膜荧光信号检测系统所测数据与碘量法误差最大为5.15 μmol/L,两种方法变化趋势相同。此系统可以作为一种海水溶解氧测量仪器,具有良好的应用价值。     

图像处理技术的荧光磁粉探伤法

简述了荧光磁粉探伤法的发展历史和研究现状,对荧光磁粉探伤技术中的多种图像处理技术进行了归纳总结,并对某些图像处理算法用MATLAB进行了测试仿真.