(FITC/SiO2-CdTe QDs)-SiO2复合结构编码荧光纳米颗粒的制备

制备了一种(FITC/SiO2-CdTe QDs)-SiO2复合结构编码荧光纳米颗粒。荧光光谱、扫描隧道显微镜和透射电镜对FITC/SiO2和(FITC/SiO2-CdTe QDs)-SiO2等荧光纳米颗粒进行了表征。结果表明,FITC/SiO2NPs和(FITC/SiO2-CdTe QDs)-SiO2均呈球形,粒径分别约为200和300 nm,分布均匀,且具有可分辨的双重荧光信号。并用Cu2+对(FITC/SiO2-CdTe QDs)-SiO2编码荧光纳米颗粒进行了后编码。     

新型FITC掺杂的二氧化硅荧光纳米粒子的合成及其应用于pH传感的研究

将异硫氰酸荧光素(FITC)与3-氨基丙基三甲氧基硅烷(APTMS)反应制得前驱体FITC-APTMS,采用油包水微乳液法,利用APTMS与正硅酸乙酯(TEOS)的共水解与聚合作用,制备了FITC掺杂的二氧化硅核壳型荧光纳米粒子。经TEM与荧光光谱表征及光稳定性实验与染料泄露实验等,表明所制得纳米颗粒呈规则球形,粒径为(150±15)nm,具有良好的单分散性与光稳定性,不易发生染料泄露。这种纳米颗粒对pH值敏感,在pH3.6～9.7范围内,荧光强度与溶液酸度有良好的响应,其中在pH6.0～9.0之间呈良好的线性关系,此纳米颗粒能被单个小鼠神经干细胞吞噬,可应用于细胞的pH值实时监测。     

壳聚糖纳米粒子荧光探针的制备和表征

通过低分子量的壳聚糖(LCS)聚阳离子与三聚磷酸钠(TPP)的静电作用制备纳米级壳聚糖微球,并利用壳聚糖链上丰富的氨基与荧光素异硫氰酸酯(FITC)反应从而制备纳米壳聚糖微球荧光探针(NFCS)。结果表明,当壳聚糖分子量为60000,LCS与TPP的质量比为6∶1时,可得到粒度均一的球形纳米粒子,平均粒径为40±3 nm。荧光倒置显微镜观察证实FITC结合到壳聚糖微球上。荧光光谱分析显示NFCS的最大激发波长、最大发射波长与游离态FITC无显著差异。光漂白实验证实NFCS的稳定性比游离态FITC有显著提高。     

新型有机荧光染料嵌合的核壳荧光纳米材料的研制

采用油包水的反相微乳液方法,首次以羊抗人免疫球蛋白(IgG)标记的异硫氰酸荧光素(FITC)为核材料,成功地制备了FITC的核壳荧光纳米颗粒,克服了采用传统方法制备核壳荧光纳米颗粒中存在的荧光染料泄露的问题.制备的这种核壳荧光纳米颗粒比细胞小很多,且具有生物亲和性,可为纳米生物传感器件提供新型材料.基于该核壳荧光纳米颗粒的标记方法也为生物医学提供了一种新型的非同位素分析方法.     

链霉亲和素-异硫氰酸荧光素偶联核壳型Fe_3O_4/Au纳米晶的合成及性质

采用改进的Polyol合成法,以PEO-PPO-PEO为表面活性剂制备了链霉亲和素-异硫氰酸荧光素偶联的Fe3O4/Au纳米粒子;利用透射电镜和X射线衍射仪分析证实了Fe3O4/Au的核壳型纳米结构,确定了其粒径和分布;采用紫外-可见吸收光谱仪和荧光光谱仪测定了所制备的纳米粒子的光学活性和荧光特性,并采用振动样品磁强计(VSM)测量了其磁化率.结果表明,所制备的Fe3O4/Au纳米粒子具有光学活性和荧光特性,以及优异的磁性.     

嵌合异硫氰酸罗丹明B核壳荧光纳米颗粒制备的新方法研究

随着纳米技术的发展,结合了纳米技术与材料制备技术而发展起来的荧光染料嵌合的核壳荧光纳米颗粒的制备为生物医学领域的研究提供了新的材料、技术和方法。何晓晓等以联钉吡啶配合物为核材料,制备了嵌合无机金属配合物的核壳荧光纳米颗粒,段菁华等用异硫氰酸荧光素FITC与蛋白质IgG相结合,     

异硫氰酸荧光素标记万古霉素的制备及其与细菌相互作用的荧光检测

以异硫氰酸荧光素(FITC)标记万古霉素(Vanco)制备了FITC-Vanco(FV),FV经高效液相制备色谱纯化后,进行了质谱结构鉴定。分别通过荧光分光光度计和流式细胞仪(FCM)测定不同浓度FV培养基中培养细菌细胞的荧光强度。结果显示,所制备的荧光探针对5种细菌有特异性结合,用荧光强度可表征细胞结合抗生素的数量,对细菌耐药机制研究和细菌对万古霉素作用敏感性的测试有应用价值。     

催化碘酸钾氧化异硫氰酸荧光素荧光猝灭法测定痕量硒

基于异硫氰酸荧光素(FITC)可发射强而稳定的荧光信号,KIO3能氧化FITC而发生荧光猝灭,Se(Ⅳ)使FITC的荧光强烈猝灭,Se(Ⅳ)的含量与ΔF值呈线性关系,建立催化KIO3氧化FITC荧光猝灭法测定痕量硒的新方法.方法的线性范围为0.012～2.000×10-15g Se(Ⅳ)/mL,工作曲线回归方程ΔF=1.18+72.74CSe(Ⅳ)(×10-15g/mL)(n=6,r=0.9997),检出限为2.1×10-18g/mL(n=11).分别对Se(Ⅳ)浓度0.012和2.000×10-15g/mL进行7次测定,RSD依次为2.8%和3.5%.用于实际样品中痕量硒的测定和人体疾病的诊断与预报,结果满意.同时探讨了催化荧光猝灭法测定痕量硒的反应机理.     

异硫氰酸荧光素标记万古霉素的制备及其与细菌相互作用的荧光检测

以异硫氰酸荧光素（FITC）标记万古霉素（Vanco）制备了FITC Vanco（FV）,FV经高效液相制备色谱纯化后,进行了质谱结构鉴定。 分别通过荧光分光光度计和流式细胞仪（FCM）测定不同浓度FV培养基中培养细菌细胞的荧光强度。 结果显示,所制备的荧光探针对5种细菌有特异性结合,用荧光强度可表征细胞结合抗生素的数量,对细菌耐药机制研究和细菌对万古霉素作用敏感性的测试有应用价值。     

新型铕配合物二氧化硅荧光纳米粒子DPPDA-Eu~(3+)/SiO_2的制备与表征

本文首先合成配位体4,7-二苯基-1,10-菲罗啉-2,9-二羧酸(DPPDA,C_(26)H_(16)N_2O_4)及铕配合物DPPDA-Eu~(3+)((C_(26)H_(16)N_2O_4)_2Eu·15H_2O),然后采用反相微乳液法,通过正硅酸乙酯和3-氨丙基三甲氧基硅烷的共水解、聚合作用成功制备出表面带氨基的二氧化硅包裹铕配合物DPPDA-Eu~(3+)的核壳型荧光纳米颗粒DPPDA-Eu~(3+)/SiO_2。利用透射电子显微镜、荧光光谱、紫外-可见光谱等手段进行表征,并进行了光稳定性、荧光泄露与氨基测定等实验,结果表明所制备的纳米粒子呈规则球状,大小均匀,粒径为80±8nm,具有良好的单分散性和光稳定性,不易发生荧光分子从二氧化硅壳层中泄露,纳米粒子表面带有氨基,可不需要进行表面修饰而直接与生物分子反应。该纳米粒子可望作为一种新型的稀土荧光探针应用于时间分辨荧光免疫分析、生物芯片及生物传感器等。     

Detection of paraoxon by immobilized organophosphorus hydrolase in a Langmuir–Blodgett film

Langmuir–Blodgett (LB) film deposition technique was employed for the immobilization of organophosphorus hydrolase (OPH). OPH enzyme was covalently bonded to a fluorescent probe, fluorescein isothiocyanate (FITC), and used as a biological recognition element. Under optimal experimental conditions, OPH monolayers were deposited onto the surface of silanized quartz slides as LB film and utilized as a bioassay for the detection of paraoxon. Two different methods were employed for detection of paraoxon: the fluorescence quenching of the fluorescence probe (FITC) covalently bonded to OPH and the UV–vis absorption spectrum of the paraoxon hydrolysis product. The UV–vis absorption measurement demonstrated a linear relationship between the absorbance at 400 nm and the concentration of paraoxon solutions over the range of 1.0 × 10⁻⁷–1.0 × 10⁻⁵ M (0.27–27 ppm). By observing the FITC fluorescence quenching, the concentration of paraoxon can be detected as low as 10⁻⁹ M (S/N = 3). The research described herein showed that the LB film bioassay had high sensitivity, rapid response time and good reproducibility.     

新型可用于荧光标记的α-氰基丙烯酸酯单体的合成及在小鼠活体成像中的应用

设计合成了新型含有荧光基团的α-氰基丙烯酸酯单体,并与其它α-氰基丙烯酸酯单体共聚,得到产生荧光的聚氰基丙烯酸酯材料.将其包埋在小鼠背部肌肉层,可获得良好的荧光成像效果.通过对荧光强度的监测,初步研究了聚氰基丙烯酸酯材料中的侧链酯基在小鼠体内的降解情况.单体合成是以蒽合氰基丙烯酸和4,4'-二甲氧基三苯基-氨基己醇为原料,得到蒽合氰基丙烯酸(4,4'-二甲氧基三苯基-氨基己醇)酯,脱保护后再将异硫氰酸荧光素以化学键合的方式标记在末端氨基上,脱蒽还原烯双键后,得到可用于荧光标记的α-氰基丙烯酸(异硫氰酸荧光素-氨基己醇)酯单体.反应中间体及单体结构采用核磁共振氢谱和质谱进行表征.该单体及其高聚物均可在激发光(488 nm)和发射光(525 nm)条件下观察到明显荧光.     

微流控芯片毛细管电泳激光诱导荧光检测法测定片剂中盐酸美西律的含量

建立了微流控芯片毛细管电泳激光诱导荧光检测法测定片剂中盐酸美西律含量的方法,对衍生条件和电泳条件进行了系统的考察。盐酸美西律经异硫氰酸荧光素(FITC)40℃衍生6h,以20 mmol/L硼砂为电泳缓冲溶液,进样30s后,分离电压2000V,可在1 min内完成一次检测。方法的检出限为0.022 mg/L、线性范围0.108～1.079 mg/L、相关系数0.994,加标回收率为99.7%～102.3%,方法适用于盐酸美西律的检测和质量控制。     

Solid-support fluorescent derivatization of picomoles of protein at low concentration with FITC

A new method based on solid-support reaction is described to realize fluorescent derivatization of proteins at concentrations as low as 10⁻⁸ M. A simple, low-cost homemade capillary C18 cartridge was fabricated as the solid-support reactor. Using bovine serum albumin (BSA) as a test protein, we demonstrated that the protein can be captured by this reactor and then labeled by fluorescein isothiocyanate (FITC, isomer I) on solid-support. Unwanted fluorescent intruder (excrescent FITC and products of secondary reactions) were removed from target easily. The analysis by nano-HPLC with laser-induced fluorescence (LIF) detection was described. The effect of reaction conditions on the derivatization has been evaluated and discussed. The use of the solid-support reactor allows easy handling of as little as 8.5 pmol of BSA. A fraction from weak anion-exchange chromatography (WAX) of human liver extract was used as an illustrative example of application to real samples.     

Glass transition activation energy of CdS/PMMA nano-composite and its dependence on composition of CdS nano-particles

CdS/PMMA nano-composites at different weight percent of CdS (0, 2, 4, 6, and 8) have been prepared using solution casting method. The obtained nano-composites are characterized through the transmission electron microscope (TEM). The differential scanning calorimetry (DSC) measurements have been done on the nano-composites at different heating rates. The peak glass transition temperature is determined using the DSC thermograms. It is found that the glass transition temperature increases with the increase of CdS content up to 6 wt% and then decreases for higher weight percent (8). It is explained on the basis of molecular motion of PMMA, which is restricted when CdS is added into PMMA. An effort is also made to study the activation energy of glass transition in the case of nano-composites of different weight percent of CdS. Variation of activation energy with CdS nano-particle concentration has also been theoretically predicted by using an empirical relation. Thermal stability of these nano-composites has been explained with the help of activation energy in the glassy region.     

STUDIES ON COMBUSTION BEHAVIOR OF NR/MMT NANO-COMPOSITES BY CONE CALORIMETER

The NR/modified montmorillonite(EMT)nano-composites were prepared by mechanical mixing and reacting in situ with glycidyl methacrylate.Under 30 kW.m~(-2)of heat flux,the combustion behavior of the nano-composites was studied with cone calorimetry,and PHRR,THR,EHC,TSR and MLR were tested.The results showed that the nano- composite had improved mechanical properties and flame retardance properties,and to some extent,the nano-composite had smoke suppress effect.Compared with pure NR,the PHRR,EHC and SPR of the nano-composite reduced by 34%,21% and 16.8%,respectively.     

An improved method for ratiometric fluorescence detection of pH and Cd using fluorescein isothiocyanate–quantum dots conjugates

In this study, thioglycolic acid capped-CdTe quantum dots (QDs) were modified by polyethylenimine (PEI), and then combined with fluorescein isothiocyanate (FITC) to fabricate FITC–CdTe conjugates. The self-assembly of FITC, CdTe and PEI was ascribed to electrostatic interactions in aqueous solution. The resulting conjugates were developed toward two routes. In route one, ratiometric photoluminescence (PL) intensity of conjugates (I_FITC/I_QDs) was almost linear toward pH from 5.3 to 8.7, and a ratiometric PL sensor of pH was favorable obtained. In route two, firstly added S²⁻ induced remarkable quenching of QDs PL peak (at the “OFF” state), which was restored due to following addition of Cd²⁺ (at the “ON” state). In the conjugates, successive introduction of S²⁻ and Cd²⁺ hardly influenced on FITC PL peaks. According to this PL “OFF-ON” mode, a ratiometric PL method for the detection of Cd²⁺ was achieved. Experimental results confirmed that the I_FITC/I_QDs exhibited near linear proportion toward Cd²⁺ concentration in the range from 0.1 to 15 μM, and the limit of detection was 12 nM. Interferential experiments adequately testified that the proposed sensors of pH and Cd²⁺ were practicable in real samples and complex systems. In comparison with conventional analytical techniques, the ratiometric PL method was simple, rapid, economic and highly selective.     

银二氧化硅核壳增强异硫氰酸荧光素酯滤纸基质室温磷光法检测赖氨酸

银二氧化硅核壳( Ag@ SiO2)可使异硫氰酸荧光素酯(FITC)产生金属增强室温磷光(MERTP).当所研究体系加入赖氨酸时,其MERTP猝灭.据此,建立了检测赖氨酸的新方法.在FITC和Ag@ Si02的加入量之比为1∶1.5,pH- 8.0时,本方法检测赖氨酸的检出限为0.270 μmol/L;线性范围为1.50～90.5 μmol/L,人二合成样品加标回收率为97.0％～108.0％;相对标准偏差为2.1％(n=9).本方法用于检测赖氨葡锌颗粒和赖氨酸磷酸氢钙片中的赖氨酸,结果满意.     

基于荧光素的荧光纳米纤维的制备与表征

以电纺聚丙烯腈(PAN)纳米纤维为起始物, 经乙二胺改性后, 再利用Mannich反应将荧光素共价连接于PAN纳米纤维薄膜表面. 用荧光光谱、 扫描电镜和红外光谱进行了结构表征. 结果表明, 利用荧光素对静电纺丝薄膜表面进行修饰, 获得了很强的荧光信号, 证明了方法的可行性.