点击化学制备新型手性配体交换色谱固定相

采用点击化学反应制备了一种新型L-脯氨酰胺衍生物键合手性配体交换色谱固定相.硅胶与γ-氯丙基三乙氧基硅烷反应后,再与叠氮化钠反应制备得到叠氮化硅胶. 在甲醇溶液中,以溴化亚铜为催化剂,叠氮化硅胶与合成的手性选择子N-炔丙基脯氨酰胺,室温反应48 h,而键合上手性官能团.手性选择子的键合量达0.47 mmol/g,操作简单,反应条件温和.制备的手性固定相以0.2 mmol/L Cu(Ac)2水溶液为流动相,在配体交换模式下拆分了8种D,L-氨基酸,对映体选择因子α在1.14～2.42之间.手性分离能力和稳定性研究表明,点击化学在手性配体交换色谱固定相的制备中具有极大潜力.     

硅胶键合手性配体交换色谱固定相拆分α-氨基酸

用简易的方法制备了铜(Ⅱ)—L—羟脯氨酸键合手性固定相；在所制备的手性固定相上，用配体交换色谱法研究了pH值、温度、中心离子浓度及流速对α—氨基酸对映体拆分的选择性和分离度的影响，选择了合理的色谱分离条件；结果表明，该固定相在配体交换模式下，可对部分常见氨基酸进行良好分离。     

酚醛树脂为载体的手性螯合树脂的合成与性能

以交联聚苯乙烯为载体的手性螯合树脂与过渡金属离子形成的络合物作配体交换色谱固定相,可拆分多种DL-氨基酸。但载体疏水性强,氮基酸在色谱过程中传质阻力大,保留时间长;硅胶键合的配体交换色谱手性相亲水性好,但柱容量小。我们通过2-羟基丙撑间隔臂将L-脯氨酸功能基联于球形酚醛树脂上,合成了手性螯合树脂(Ⅰ)。以其铜(Ⅱ)络合物作配体交换色谱固定相,对多种DL-氨基酸呈现拆分活性,且保留时间少于1h。     

β-氨基酸对映体在键合型配体交换色谱固定相上的分离

制备了以L-α-氨基酸为手性配体和球型多孔硅胶为基质的键合型手性配体交换色谱固定相,用于β-氨基酸对映体的拆分。考察了硅胶基质、配体、流动相pH值、中心金属离子浓度和流动相阴离子等因素对5种β-苯丙氨酸对映体分离的影响,由此确立最佳色谱分离条件为以BaseLine硅胶为基质键合L-羟脯氨酸的手性固定相,5.0mmol/L和pH4.6的CuSO4溶液为流动相,紫外检测波长为254nm。在此条件下5种β-氨基酸对映体均可在35min内得到分离,分离因子在1.49~1.77之间。结果表明该方法操作简便,成本低廉,可用于β-氨基酸对映体的分离和分析。     

新型L-羟脯氨酸聚合物键合手性固定相的制备及对手性化合物的拆分

以单分散亲水性交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为载体,制备新型L-羟脯氨酸聚合物键合高效手性配体交换固定相。该固定相在配体交换分离模式下,以0.2mol/LNaAc和0.1mmol/LCu(Ac)2水溶液(pH5.2)为流动相,柱温为30℃～50℃,对衍生和非衍生的D,L-氨基酸和α-羟基酸等9种手性化合物进行了高效液相色谱拆分。详细考察了流动相pH值、温度、流速和进样量对手性分离的影响,选择了合适的色谱分离条件。结果表明,所拆分的9种手性化合物,有5种手性化合物能得到基线分离,最好的分离因子α=2.32。     

新型手性配体交换色谱固定相的制备及应用

 合成了 2 -(2 -羟基 -3 -烷氧基 )丙基 -(S) -1 ,2 ,3 ,4-四氢 -3 -异喹啉羧酸手性选择子 ,制备了两种新型涂渍手性配体交换色谱固定相 ,拆分了某些 DL-氨基酸 ,比较了 DL-氨基酸在两种手性相上的色谱分辨。     

原子转移自由基聚合技术制备新型手性配体交换色谱固定相及对手性化合物的拆分

采用原子转移自由基聚合(ATRP)技术, 以溴代硅胶为引发剂, CuCl/2,2'-联吡啶(Bpy)为催化体系, 水为溶剂, N-丙烯酰基-L-脯氨酸为单体, 室温下在硅胶表面进行聚合反应, 制得硅胶接枝聚N-丙烯酰基-L-脯氨酸分子刷. 通过改变ATRP反应体系中单体的量, 制备了3种不同键合量且键合量可控的手性配体交换色谱固定相, 利用元素分析和热重分析对其进行表征. 考察了配体接枝率、 流动相Cu²⁺浓度、 pH值和柱温等对DL-氨基酸和α-羟基酸拆分的影响, 优化了色谱分离条件, 探讨了拆分过程的热力学. 结果表明, 所合成的手性配体交换色谱固定相能够分离9种DL-氨基酸和α-羟基酸, 其中DL-酪氨酸、 DL-色氨酸和DL-苏氨酸3种氨基酸可同时进行拆分, 且拆分过程由熵控制.     

单分散树脂键合手性配体交换色谱固定相拆分DL-氨基酸

以单分散交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为基质合成了L-脯氨酸键合手性配体交换固定相,并用于DL-氨基酸的直接光学拆分,考察了流动相pH值、金属离子浓度、流速及温度等因素对DL-氨基酸对映体拆分的影响。结果表明,该固定相在配体交换色谱模式下可对多对DL-氨基酸进行良好的拆分。     

α-氨基酸在L-脯氨酸手性配体交换色谱固定相上的分离

合成了L-脯氨酸硅胶键合手性配体交换色谱固定相，并用于α-氨基酸的直接光学分离，详细考察了流动相pH值、金属离子浓度、流速、柱温以及进样量等因素对分离效果的影响，从而进一步优化了色谱分离条件。     

硅胶键合手性配体交换固定相键合量对α-氨基酸拆分的影响

 合成了两种不同键合量的L 脯氨酸硅胶键合手性配体交换固定相 ,装柱后利用配体交换法分离了一系列的α 氨基酸。实验结果表明键合量不同的固定相对α 氨基酸的拆分能力差别较大。     

基于银增强金标记物的阳极溶出伏安免疫分析用于补体第三成分的测定

分子印迹是制备对特定分子具有专一性结合能力的聚合物的技术,所制备的聚合物被称为分子印迹聚合物（Molecularly imprinted polymers,MIPs）,此类聚合物在分离提纯、模拟酶和传感器等方面均显示出广阔的应用前景,迄今,小分子化合物的印迹技术已经十分成熟。     

RECENT ADVANCES IN THE PREPARATION OF MOLECULARLY IMPRINTED POLYMERS VIA CONTROLLED RADICAL POLYMERIZATION TECHNIQUES

Molecular imprinting technique is a simple and efficient method for the preparation of polymer materials （i. e., molecularly imprinted polymers, MIPs） with tailor-made recognition sites for certain target molecules. The resulting MIPs have proven to be versatile synthetic receptors due to their high specific recognition ability, favorable mechanical, thermal and chemical stability, and ease of preparation. Recent years have witnessed significant progress in the synthesis and applications of MIPs. This review focus on the recent developments and advances in the preparation of MIPs via various controlled radical polymerization techniques.     

Surface-imprinted polymers in microfluidic devices

Molecularly imprinted polymers are generated by curing a cross-linked polymer in the presence of a template. During the curing process, noncovalent bonds form between the polymer and the template. The interaction sites for the noncovalent bonds become "frozen" in the cross-linking polymer and maintain their shape even after the template is removed. The resulting cavities reproduce the size and shape of the template and can selectively reincorporate the template when a mixture containing it flows over the imprinted surface. In the last few decades the field of molecular imprinting has evolved from being able to selectively capture only small molecules to dealing with all kinds of samples. Molecularly imprinted polymers (MIPs) have been generated for analytes as diverse as metal ions, drug molecules, environmental pollutants, proteins and viruses to entire cells. We review here the relatively new field of surface imprinting, which creates imprints of large, biologically relevant templates. The traditional bulk imprinting, where a template is simply added to a prepolymer before curing, cannot be applied if the analyte is too large to diffuse from the cured polymer. Special methods must be used to generate binding sites only on a surface. Those techniques have solved crucial problems in separation science as well as chemical and biochemical sensing. The implementation of imprinted polymers into microfluidic chips has greatly improved the applicability of microfluidics. We present the latest advances and different approaches of surface imprinting and their applications for microfluidic devices.     

表面印迹聚合物及其在微流控器件中的应用

分子印迹聚合物是通过在模板存在下固化交联的聚合物制备的.在固化过程中,聚合物和模板间形成非共价键.这些非共价结合位点被"冻结"在交联的聚合物中,即使移去模板后也依然维持他们的形状.余下的空穴与模板的尺寸和形状一致,并且可以选择性地从流过的混合物中俘获模板物质.在近几十年中,分子印迹的领域由选择性俘获小分子扩展到处理各种类型的样品.分子印迹聚合物(MIP)被用于分析种类繁多的样品,比如金属离子、药物分子、环境污染物、蛋白、病毒以至整个细胞.本文中我们综述相对较新的领域——表面印迹,这是一种可以用来生成相对较大的生物相关模板的印迹方法.传统的整体印迹法是直接在固化前将模板加入预聚体中,因而不适用于那些大到无法从固化后的聚合物中扩散出来的物质.要仅在表面上生成结合位点,必须要使用特别的方法,由此产生的表面印迹技术解决了分离科学以及化学和生物化学监测的重要问题.将印迹聚合物植入微流控芯片,大大扩展了微流体技术的适用性.本文叙述表面印迹最新的进展以及不同的实施手段,以及它们在微流控器件中的应用.     

表面分子印迹材料和技术在分离分析中的应用进展

复杂体系的高选择性分析对分离新材料和新方法提出了迫切需求。分子印迹聚合物（MIPs）以其特异性高、化学稳定性好、制备简单且成本低等优点,在高选择性分离分析中展现出巨大的应用前景。但以本体聚合为代表的传统合成方法获得的MIPs存在识别位点位于聚合物内部难以识别、模板分子洗脱不彻底、传质速率慢、结合容量低等问题。表面印迹技术制备的核-壳型表面分子印迹材料是解决上述难题的有效途径。通过核体和壳层结构的设计和构建,表面分子印迹材料还可具备多功能、多响应的特性,适于现代分离分析对快速、高效、高选择性的要求。该文主要综述了近几年表面分子印迹技术在样品前处理、化学/生物传感分析及靶向药物递送领域的应用进展。     

Recent advancement of carbon nanomaterials engrained molecular imprinted polymer for environmental matrix

Sample preparation techniques have always been considered as a complex issue in the analytical process. Most of the sample preparation techniques show a lack of selectivity. Molecularly imprinted polymer (MIP) is a synthetic approach for sample preparation technique that has the ability of selective extractions. Generally, MIPs are selective sorbent, MIPs are capable of binding a molecule or its geometrical analogues. The imprinted polymers own particular voids exclusively framed for the aimed target analytes. These MIPs have been synthesized through a complex route of polymerization using a dedicated crosslinker, a template and function bound specific monomers (mainly interacting with the template). Despite having various pros like selectivity, morphological predictability, chemical & thermal stability, points alike binding site heterogeneity, partial template removal, and limited application pose a challenge. In this regard, a relatively newer carbon-based MIP method is explored as the molecular imprinting technique in various environmental samples. This paper describes the current scenario in the field of molecular-based imprinting technology using different carbon engrained materials and highlights the latest applications in this field and suggest proposals for the prospect in the area of the MIP.     

Surface molecularly imprinted nanowires for biorecognition

Herein we present a novel method for preparation of surface molecularly imprinted size-monodisperse nanowires. The imprint molecule is immobilized on the pore walls of a silane-treated nanoporous alumina membrane. The nanopores are then filled with the monomer mixture, and the polymerization is initiated. The alumina membrane is subsequently removed by chemical dissolution, leaving behind polypyrrole nanowires with glutamic acid binding sites situated at the surface. These nanowires can be dissolved in aqueous media, and their applications therefore should be compatible with procedures in which biological antibodies might otherwise be used. For example, the analyte molecule can be tagged with various markers, such as fluorescence probes and enzymes, whereby the problem of steric hindrance is avoided. Furthermore, these surface-imprinted nanowires are likely suited for imprinting and recognition of large-molecular-weight peptides and proteins. Related work is currently being undertaken in our laboratory.     

模板结构与分子印迹效果间关系的研究

以一些分子量和体积都较小的简单化合物作为模板分子,合成分子印迹聚合物 。通过总结43种化合物的分子印迹聚合物的色谱数据,来研究模板分子的分子量、 作用位点数目、分子刚性等因素与印迹效果的关系。根据免疫学中免疫原性的定义 ,我们提出“印迹原性”的概念,即,化合物能够产生印迹效应的性质称为印迹原 性;具有印迹原必的化合物称为印迹原;并讨论了具有较强选择性的印迹原的化学 基础。所得到的结论将有助于对分子印迹聚合物的识别机理的进一步理解,并且对 于根据模板分子性质预测MIP分子识别能力将具有一定的指导意义。     

Preparation and application of hollow molecularly imprinted polymers with a super‐high selectivity to the template protein

Protein‐imprinted polymers with hollow cores that have a super‐high imprinting factor were prepared by etching the core of the surface‐imprinted polymers that used silica particles as the support. Lysozyme as template was modified onto the surface of silica particles by a covalent method, and after polymerization and the removal of template molecules, channels through the polymer layer were formed, which allowed a single‐protein molecule to come into the hollow core and attach to the binding sites inside the polymer layer. The adsorption experiments demonstrated that the hollow imprinted polymers had an extremely high binding capacity and selectivity, and thus a super‐high imprinting factor was obtained. The as‐prepared imprinted polymers were used to separate the template lysozyme from egg white successfully, indicating its high selectivity and potential application in the field of separation of protein from real samples.     

Novel functional monomer for the electrochemical synthesis of highly affine epitope-imprinted polymers

To address the lack of functional monomer diversity for the electrosynthesis of protein-selective molecularly imprinted polymers (MIPs), we introduce a new concept able to lead to a new class of functional monomers. This is based on conjugating an electropolymerizable monomer unit (umbelliferone) to an amino acid for closer mimicking of protein-based natural affinity ligands such as antibodies. As the first representative of this class of monomers an aspartate-umbelliferone (Asp-UMB) conjugate was synthesized and here we provide the proof for its suitability to generate highly affine MIPs for proteins by epitope imprinting. As model we used a heptapeptide (GFNCYFP) stemming from the receptor binding domain (RBD) of the SARS-CoV-2 spike protein to generate epitope-imprinted polymers able to recognize the parent RBD protein. For rapid optimization and assessment of the binding kinetics we prepared MIP microarrays on surface plasmon resonance imaging (SPRi) chips. First the peptides were microspotted on the bare gold surface of the chips followed by the electropolymerization of Asp-UMB. This resulted in ca. 2 nm thick, highly uniform, and electrically insulating polymer film, well suited both for hierarchical epitope imprinting and SPRi read-out. Taking advantage also of the on-chip optimization enabled by the microarray format the increased functional diversity of the new monomer resulted in highly affine MIPs with equilibrium dissociation constants in the lower picomolar range.