Biotin-derivatized poly(L-lysine)-g-poly(ethylene glycol):: A novel polymeric interface for bioaffinity sensing
Biotin-derivatized poly(L-lysine)-g-poly(ethylene glycol):: A novel polymeric interface for bioaffinity sensing
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DOI：
10.1021/la010913m
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发表时间：
2002-01-08
期刊：
影响因子：
3.9
通讯作者：
Spencer, ND
中科院分区：
文献类型：
--
作者：
Huang, NP;Vörös, J;Spencer, ND
开发了一种新型生物传感器界面，该界面利用聚乙二醇接枝生物素化共聚物的自发表面组装，并在光波导芯片上进行了测试，基于顺序固定(Strept)亲和素和生物素化的山羊抗兔免疫球蛋白(alphaRIg G-bitin)作为捕捉分子的模型免疫分析，以检测兔免疫球蛋白(Rigg)靶分子。含Nb的光波导光模式光谱分析。使用氧化物波导层来定量和原位监测(生物素化)共聚物在波导层表面的自发吸附，所产生的附着层对非特异性蛋白质吸附的阻力，以及模型免疫分析的每一步的质量吸收。聚(L-赖氨酸)-g-聚环氧乙烷(PLL-g-PEG)是一种聚阳离子共聚物，通过静电作用从水溶液中自发吸附到带负电荷的表面。它形成具有密集堆积的聚乙二醇链的单层。合成了在0、20、30或50%的聚乙二醇链上带有末端生物素基团的PLL-g-PEG接枝共聚物，并将其组装到氧化NbO表面(中性pH下带负电荷)。通过调节生物素在聚合物分子中的接枝率或从相应的混合溶液中组装出混合的[PLL-g-PEG/PEGBiotin+PLL-g-PEG]附着层来调节生物素的表面浓度。这些生物素化的表面被证明对血清的非特异性吸附具有高度的抵抗力，同时仍然允许链霉亲和素、亲和素或中性亲和素等连接蛋白的特定表面结合。固定化连接蛋白的量与生物素的表面浓度密切相关。然而，α-RIgG-生物素和RIGG的后续吸附行为以更复杂的方式依赖于每个单独的表面修饰步骤，并根据特定和非特定的相互作用以及覆盖层内的取向和空间排斥效应进行了讨论。在检测信号背景比方面，[PLL-g-PEG/PEGbiotin//NeutrAvidin//alphaRIgG-biotin]体系结构作为蛋白质生物亲和力检测的接口体系结构表现出特别有前途的性能。
A novel biosensor interface exploiting the spontaneous surface assembly of a polyeationic, PEG-grafted, biotinylated copolymer was developed and tested on optical waveguide chips in a model immunoassay based on sequential immobilization of (strept)avidin and biotinylated goat antirabbit immunoglobulin (alphaRIgG-biotin) as a capture molecule to sense the rabbit immunoglobulin (RIgG) target molecule. Optical waveguide lightmode spectroscopy with niobium. oxide waveguiding layers was used to monitor quantitatively and in situ the spontaneous adsorption of the (biotinylated) copolymer onto the waveguide surface, the resistance of the resulting adlayer to nonspecific protein adsorption, and the mass uptakes in each step of the model immunoassay. Poly(L-lysine)-g-poly(ethylene oxide) (PLL-g-PEG) is a polycationic copolymer that adsorbs spontaneously from aqueous solutions onto negatively charged surfaces via electrostatic interactions. It forms monolayers with densely packed PEG chains. PLL-g-PEG graft copolymers carrying terminal biotin groups on 0, 20, 30, or 50% of the PEG chains were synthesized and assembled onto the surface of niobium oxide (negatively charged at neutral pH). The surface concentration of biotin was tailored by adjusting the biotin grafting ratio in the polymeric molecule or by assembling mixed [PLL-g-PEG/PEGbiotin + PLL-g-PEG] adlayers from the corresponding mixed solutions. These biotinylated surfaces are shown to be highly resistant to nonspecific adsorption from serum while still allowing for the specific surface binding of the linkage proteins: streptavidin, avidin, or neutral avidin. The amount of immobilized linkage protein is shown to be closely related to the biotin surface concentration. The subsequent adsorption behavior of alphaRIgG-biotin and RIgG, however, depends in a more complex manner on each individual surface modification step and is discussed in the light of specific and nonspecific interactions, as well as of orientational and steric repulsion effects within the adlayers. In terms of the sensing signal-to-background ratio, the [PLL-g-PEG/PEGbiotin//NeutrAvidin//alphaRIgG-biotin] architecture demonstrated particularly promising performance as an interface architecture for bioaffinity sensing of proteins.