TNT分子印迹聚合物微球的合成与性能研究

以三硝基甲苯(TNT)为模板分子,EDMA为交联剂,采用沉淀聚合法制备了TNT分子印迹微球.讨论了溶剂用量、模板分子用量、功能单体种类等对分子印迹微球的形貌及吸附性能的影响;利用紫外吸收光谱和BET表征了印迹聚合物微球的结合位点相互作用与印迹孔穴结构;通过平衡吸附和选择性吸附实验,研究了印迹聚合物微球的吸附性能和选择性识别性能.结果表明,以丙烯酰胺为功能单体制备的分子印迹聚合物为规则的球形,内部含有分子印迹孔穴,微球的粒径为1～2μm.印迹聚合物微球可在30 min内达到吸附平衡,在1 mmol/L的TNT乙醇溶液中,印迹聚合物微球的平衡吸附量为32.5 mmol/kg,对TNT分离系数为25.19,具有较好的特异性吸附能力,并可选择性识别TNT分子.     

光接枝表面修饰法制备牛血红蛋白的分子印迹微球

聚苯乙烯球载体表面经引发转移终止剂修饰后, 采用光接枝表面印迹方法制备了以牛血红蛋白(BHb)为模板分子、丙烯酰胺为功能单体和N,N′-亚甲基双丙烯酰胺为交联剂的分子印迹聚合物微球(MIP). 进一步采用红外光谱(IR)、扫描电子显微镜(SEM)和元素分析对聚合物微球进行了表征, 证实了载体表面成功地接枝了分子印迹层, 并研究了其吸附性能和分子识别选择性能. 结果表明, 采用光接枝表面修饰法制备的分子印迹微球对模板分子有着很好的吸附容量和识别选择性.     

具有高选择性吸附的表面分子印迹磁性纤维素微球的制备与性能

以纤维素和纳米Fe₃O₄为原料制得磁性纤维素微球, 在纤维素微球表面选择合适的模板分子, 以甲基丙烯酸、 丙烯酰胺和N,N'-亚甲基双丙烯酰胺为功能单体, 采用水溶液聚合法制得表面分子印迹磁性纤维素微球. 采用傅里叶变换红外光谱(FTIR)、 X射线衍射(XRD)和振动样品磁强计(VSM)等表征了分子印迹聚合物微球的结构. 以罗丹明B(RhB)为模板分子, 通过吸附动力学与吸附热力学实验研究了表面分子印迹磁性纤维素微球对RhB的吸附性能, 结果表明, 制备的表面分子印迹磁性纤维素微球对罗丹明B具有特异性识别作用, 饱和吸附量达到0.542 mg/mg, 吸附平衡时间为10 h左右. 表面分子印迹磁性纤维素微球大大降低了对吸附环境的依赖, 并可重复利用.     

磁性分子印迹微球的制备及其对熊果酸的选择性分离

利用表面分子印迹技术,以Fe3 O4磁性纳米微球为基质材料、熊果酸为模板分子、3-氨丙基三乙氧基硅烷为功能单体、正硅酸乙酯为交联剂,制备了熊果酸磁性分子印迹纳米微球,用于熊果酸的高选择性快速分离.采用透射电子显微镜和振动样品磁强计对制备的复合纳米材料进行表征,通过吸附动力学和吸附等温线考察了制备的磁性分子印迹纳米微球的...     

制备牛血红蛋白印迹聚合物的初步研究

采用凝胶法,以丙烯酰胺为单体.N,N'-甲叉双丙烯酰胺为交联剂,制备了牛血红蛋白的分子印迹聚合物.通过考察不同单体用量对所制备的分子印迹聚合物的吸附性能的影响,得到优化制备条件.用吸附溶液的光吸收性质及电镜等对印迹聚合物的选择性吸附特性和形态特征进行表征.结果表明,制备的分子印迹聚合物对模板分子牛血红蛋白可以选择性吸附,具有很好的发展潜力.     

大黄酸分子印迹聚合物微球的制备及特性

以聚苯乙烯微球为种球,大黄酸为模板分子,采用单步溶胀聚合法在N,N-二甲基甲酰胺体系中制备了单分散分子印迹聚合物微球.用扫描电镜对微球的结构和形貌进行了表征,并研究了微球的制备条件和吸附特性.微球的凹槽可有效地增加微球的比表面积和结合位点,从而提高了模板分子的结合速率及微球的印迹容量.     

核-壳型厚朴酚印迹聚合物的制备及性能研究

以表面修饰功能基团的SiO2微球为基体,以厚朴酚为模板分子,丙烯酰胺为功能单体,丙烯酸乙二醇二甲酯为交联剂,在SiO2微球表面制备对厚朴酚具有较好选择识别能力的核-壳型印迹聚合物.采用红外光谱及扫描电镜等技术表征聚合物的结构及形态.结果表明,该印迹聚合物表面成功制备了壳层厚度约为200nm的均匀印迹层.通过静态吸附、Scatchard分析法以及竞争吸附实验研究了该聚合物的吸附性能和选择性,结果表明,它对厚朴酚形成均一结合位点,离解常数为0.19mg/mL.     

核-壳型白藜芦醇分子印迹微球研制及应用

以表面修饰乙烯基团的SiO2微球为基体,白藜芦醇为模板分子,丙烯酰胺(AA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,采用表面印迹技术制备核-壳型白藜芦醇印迹微球。采用红外光谱(IR)、扫描电子显微镜(SEM)对该分子印迹微球进行表征,结果表明,SiO2表面成功接枝一层厚度为200nm的印迹聚合物,该印迹微球颗粒分散均匀。采用高效液相色谱技术对印迹微球的吸附性进行研究表明,此印迹微球具有良好的识别性能,利用Scatchard模型分析得出印迹微球的最大吸附量分别为Qmax1=9.087mg/g和Qmax2=13.80mg/g。此印迹微球成功用于分离虎杖提取液中白藜芦醇。     

分子印迹胶体阵列检测对硝基苯酚

以对硝基苯酚(p-NP)为印迹模板,丙烯酰胺为功能单体,制备单分散的对硝基苯酚分子印迹胶体微球。通过垂直沉降法将分子印迹胶体微球自组装为分子印迹胶体阵列,采用胶带将分子印迹胶体阵列粘贴固定。固定于胶带上的分子印迹胶体阵列膜显示出良好的稳定性,而且对目标分子p-NP具有明显的光学响应。分子印迹微球吸附目标分子发生溶胀,引起胶体阵列溶涨,分子印迹胶体阵列(MICA)反射峰位置发生移动。实验结果显示,MICA随着p-NP浓度增加,反射峰红移近60 nm,MICA表面颜色由红色逐渐变为蓝紫色;而非印迹胶体阵列红移量只约40 nm。MICA简化了光子晶体凝胶传感材料的制备步骤,为开发新型高性能生化传感器材料提供了新思路。     

分子印迹纳米胶体阵列检测爆炸物的研究

以三硝基甲苯(TNT)为模板,丙烯酰胺为功能单体,采用乳液聚合法制备具有单分散性的TNT分子印迹胶体小球.通过垂直沉降法自组装,并用胶带将得到的具有蛋白石结构的分子印迹胶体阵列(MICA)固化.研究其在不同比例的甲醇/水溶液中的光学响应,并在最优检测环境下进行特异性吸附实验.实验表明,当甲醇/水的体积比为7∶3,TNT浓度为20 mmol/L时,反射峰红移近24 nm,为非印迹胶体阵列红移量的1.4倍,为TNT结构类似物的23倍.MICA在实现对光子晶体传感器制备简化的同时,提供了对TNT进行快速裸眼检测的可能性.     

Thermal stability of the crystallisation nucleant

The 2,2',4,4',6,6'hexanitrostilbene, HNS, nucleant, used in the crystallisation of 2,4,6,trinitrotoluene, TNT, was precipitated from molten TNT and examined by differential scanning calorimetry, DSC, at several stages during purification by vacuum sublimation. During purification a broad endotherm, associated with nucleant decomposition, which could be resolved into two endotherms, depending on the sublimation temperature, was observed. Pure nucleant prepared at 70C showed a similar behaviour during thermal annealing for extended periods of time at >85C. Thus TNT, retained in the recrystallised HNS nucleant, may be migrating during the purification process or may occupy a range of lattice sites, which exhibit different activation energies for migration to the surface of the solid during thermal decomposition of the nucleant. Loss of TNT from the nucleant, during purification, could produce some free HNS. The activation energy for nucleant decomposition, which may be a two-stage processes with the initial mobility of the TNT being the limiting reaction, was estimated to be 210 kJ mol^–. The lattice sites available for the TNT in the host HNS nucleant require elucidation and are the subject of further studies to be published at a later date.     

新型固相微萃取膜及其在分析沙土中梯恩梯的应用

本文用酰胺类化舍物和气相色谱固定液制备了一种新型固相微萃取膜，应用该类固相微萃取膜成功地分离了沙土中炸药梯恩梯，并利用气相色谱／质谱联用技术对分离后的样品进行了分析。     

Biosensor-based on-site explosives detection using aptamers as recognition elements

Reliable observation, detection and characterisation of polluted soil are of major concern in regions with military activities in order to prepare efficient decontamination. Flexible on-site analysis may be facilitated by biosensor devices. With use of fibre-optic evanescent field techniques, it has been shown that immunoaffinity reactions can be used to determine explosives sensitively. Besides antibodies as molecular recognition elements, high-affinity nucleic acids (aptamers) can be employed. Aptamers are synthetically generated and highly efficient binding molecules that can be derived for any ligand, including small organic molecules like drugs, explosives or derivatives thereof. In this paper we describe the development of specific aptamers detecting the explosives molecule TNT. The aptamers are used as a sensitive capture molecule in a fibre-optic biosensor. In addition, through the biosensor measurements the aptamers could be characterised. The advantages of the aptamer biosensor include its robustness, its ability to discriminate between different explosives molecules while being insensitive to other chemical entities in natural soil and its potential to be incorporated into a portable device. Results can be obtained within minutes. The measurement is equally useful for soil that has been contaminated for a long time and for urgent hazardous spills.     

Photolysis by UVA–Visible Light of TNT in Ethanolic,Aqueous-Ethanolic,and Aqueous Solutions According to Electrospray and Aerodynamic Thermal Breakup Droplet Ionization Mass Spectrometry

The mechanism of photolytic degradation of 2-4-6-trinitrotoluene (TNT) by UVA–visible light (>320 nm) in ethanolic, aqueous-ethanolic, and aqueous solutions was investigated by electrospray and aerodynamic thermal breakup droplet ionization mass-spectrometric analyses. For the photolysis, a DRK-120 mercury-quartz lamp was used. Products of the photolysis reaction were compared with known products of TNT transformation in the environment. Because the photochemistry of some compounds in alcohols (in contrast to aqueous solutions) features a transfer of electrons from the solvent to the light-excited compound, we believe that the efficiency of photolysis (polymerization) of TNT in ethanol and aqueous-ethanolic solutions is based on this mechanism.     

Non-aerosol detection of explosives with a continuous flow immunosensor

Contamination of groundwater, soil, and the marine environment by explosives is a global issue. Identification, characterization and remediation are all required for a site recognized as contaminated with 2,4,6-trinitrotoluene (TNT) or hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). For each step, a method to accurately measure the contaminant level is needed. This paper reviews some of the current methods with emphasis on a single biosensor developed in our laboratory. Current regulatory methods require samples to be sent off-site to a certified laboratory resulting in time delays up to a month. A continuous flow biosensor for detection of explosives has been developed and tested for the rapid field screening of environmental samples. The detection system is based on a displacement immunoassay in which monoclonal antibodies to (TNT) and RDX are immobilized on solid substrates, allowed to bind fluorescently labeled antigens, and then exposed to explosives in aqueous samples. Explosive compounds present in the sample displace proportional amounts of the fluorescent label, which can then be measured to determine the original TNT or RDX concentration. The system can accurately detect ppb to ppt levels of explosives in groundwater or seawater samples and in extracts of contaminated soil. The biosensor has applications in environmental monitoring at remediation sites or in the location of underwater unexploded ordnance.     

Ultrasensitive detection of TNT in soil, water, using enhanced electrogenerated chemiluminescence

The ultrasensitive detection of 2,4,6-trinitrotoluene (TNT) was accomplished on the basis of sandwich-type TNT immunoassay combined with electrogenerated chemiluminescence (ECL) technology. Biotinylated anti-TNT species were attached to the surface of 1-μm diameter streptavidin-coated magnetic beads (MB) and 10-μm diameter avidin-coated polystyrene microspheres/beads (PSB) pre-loaded with ECL labels (∼7 billion hydrophobic ruthenium(II) tris(2,2′-bipyridine) (Ru^II) molecules per bead) to form anti-TNT ↔ MB and anti-TNT ↔ PSB(Ru^II) conjugates, respectively. Sandwich-type PSB(Ru^II) ↔ anti-TNT < TNT > anti-TNT ↔ MB aggregates were formed when PSB(Ru^II) ↔ anti-TNT was mixed with anti-TNT ↔ MB conjugates in the presence of analyte TNT and 2.0% bovine serum albumin blocking agent. The newly formed aggregates were magnetically separated from the aqueous reaction media and dissolved in acetonitrile containing 0.10 M tri-n-propylamine ECL coreactant-0.055 M trifluoroacetic acid-0.10 M tetrabutylammonium tetrafluoroborate electrolyte. ECL as well as cyclic voltammetric measurements were carried out with a potential scan from 0 to 2.8 V vs Ag/Ag⁺, and the integrated ECL intensity was found to be linearly proportional to the analyte TNT concentration over the range of 0.10-1000 ppt (pg mL⁻¹). The limit of detection (≤0.10 ± 0.01 ppb) is about 600× lower as compared with the most sensitive TNT detection method in the literature, and the absolute detection limit in mass (∼0.1 pg) is only ∼0.5% of that from mass spectroscopy. The approach coupled with the standard addition method was applied to measure the TNT contaminations in soil and creek water samples collected from a military training base.     

2,4,6‐Trinitrotoluene – A Useful Starting Compound in the Synthesis of Modern Energetic Compounds

This review presents history, properties, and environmental fate of 2,4,6‐trinitrotoluene (TNT). Industrial methods of TNT production are discussed, as are several energetic derivatives of TNT. The performances and applications of these TNT derivatives are also described.     

3,4-二硝基吡唑的合成

吡唑经硝化、重排、硝化三步反应合成了潜在的TNT替代物——3,4-二硝基吡唑,其结构经1H NMR和IR确证。并对第三步硝化反应条件进行了优化,单步收率41%。     

Activation mechanisms of butyrylcholinesterase by 2,4,6-trinitrotoluene, 3,3-dimethylbutyl-N-n-butylcarbamate, and 2-trimethylsilyl-ethyl-N-n-butylcarbamate

The goal of this work was to propose a possible mechanism for the butyrylcholinesterase activation by 2,4,6-trinitrotoluene (TNT), 3,3-dimethylbutyl-N-n-butylcarbamate (1), and 2-trimethylsilyl-ethyl-N-n-butylcarbamate (2). Kinetically, TNT, and compounds 1 and 2 were characterized as the nonessential activators of butyrylcholinesterase. TNT, and compounds 1 and 2 were hydrophobic compounds and were proposed to bind to the hydrophobic activator binding site, which was located outside the active site gorge of the enzyme. The conformational change from a normal active site gorge to a more accessible active site gorge of the enzyme was proposed after binding of TNT, and compounds 1 and 2 to the activator binding site of the enzyme. Therefore, TNT, and compounds 1 and 2 may act as the excess of butyrylcholine in the substrate activator for the butyrylcholinesterase catalyzed reactions.     

纳米铁粉降解水中三硝基甲苯的条件优化与降解机理

研究了纳米铁粉降解水中三硝基甲苯(TNT)的影响因素;利用傅立叶变换红外光谱和紫外光谱分析了其降解机理.结果表明:将初始浓度为80.0mg/L、pH为4.00的TNT水溶液与5.0g/L的纳米铁粉在转速200r/min、温度40℃的振荡器中反应3h,水中TNT的浓度可降至0.1mg/L以下,降解率达到99%以上;就TNT的降解机理而言,其降解过程是纳米铁粉给出电子被氧化、TNT分子中的硝基接受电子被还原的过程.