传感器类型
综述或非传感器论文
检测对象
麦胚凝集素(WGA)、花生凝集素(PNA);样品基质:水相/PBS缓冲液
检测原理
该体系并非完整传感器,而是基于糖-凝集素识别的纳米颗粒结合检测原理。两亲性糖缀合物在水中自组装为核壳纳米颗粒:四对苯(ϕ4)形成疏水核,PEG链形成亲水冠层,乳糖或GlcNAc配体暴露于表面。当加入特异性凝集素时,WGA识别GlcNAc,PNA识别乳糖/半乳糖,凝集素与颗粒表面糖配体结合后形成更大复合物,使水动力学半径增大。DLS通过自相关函数和弛豫时间分布监测布朗扩散变化,粒径增大表现为弛豫时间向长时移动;乳糖颗粒加入PNA后RH由11.8 nm增至17.2 nm,约增大50%。TEM和SAXS可进一步确认核壳结构、粒径和聚集数,为将此类糖基化纳米颗粒用于凝集素或糖链相关生物传感提供材料基础。
检测灵敏度
—
效应效果
PEG900体系形成单分散球形胶束,DLS主峰2RH约10.3 nm,TEM平均直径9.9±1.9 nm;糖基化后粒径基本不变,GlcNAc和乳糖胶束TEM平均直径分别为12.9±1.9 nm和10.9±1.9 nm。PEG600体系因亲水/疏水平衡改变形成多分散囊泡,2RH约210 nm,RG/RH=0.98,符合囊泡形貌。选择性方面,非匹配凝集素加入后DLS自相关曲线无明显变化;PNA与乳糖颗粒结合使RH从11.8 nm增至17.2 nm,WGA与GlcNAc颗粒结合引起弛豫时间分布明显移动。SAXS拟合给出核半径1.9–2.5 nm、胶束尺寸4.1–4.3 nm、聚集数59/41/30。作者认为该材料可用于诊断、药物递送和生物传感器。
传感器的构成
- 疏水核:四对苯(tetra(p-phenylene), ϕ4)刚性疏水棒段,构成胶束核并决定疏水体积分数
- 亲水冠层:聚乙二醇(PEG900/PEG600)柔性亲水链,提供水溶性并调控胶束或囊泡形态
- 表面识别配体:乳糖(Lac)或N-乙酰氨基葡萄糖(GlcNAc),经三唑连接于PEG末端并暴露于颗粒表面
- 结合对象:麦胚凝集素(WGA)或花生凝集素(PNA),特异性识别GlcNAc或半乳糖/乳糖
- 读出方式:动态光散射(DLS)、透射电镜(TEM)和小角X射线散射(SAXS),用于粒径、形貌及结合后尺寸变化表征
中文摘要
本文报道了糖基化棒-线圈两亲性体系的合成、自组装及其与凝集素的相互作用。作者采用铜催化的Huisgen环加成(click chemistry),将乳糖和N-乙酰氨基葡萄糖配体接枝到PEG-b-四对苯共轭物的亲水末端,得到两亲性糖缀合物。这些体系在水溶液中可自发组装成纳米颗粒,并通过动态光散射(DLS)、透射电子显微镜(TEM)和小角X射线散射(SAXS)进行表征。含PEG900亲水段的体系形成高度单分散的球形胶束,平均直径约10 nm;当亲水段缩短为PEG600时,亲水/疏水平衡改变,形成尺寸分布较宽的囊泡。光散射测量进一步证明糖残基暴露于胶束表面,并能与麦胚凝集素(WGA)和花生凝集素(PNA)发生特异性结合,从而支持此类糖基化胶束在生物传感器器件中的应用潜力。
英文摘要
This work describes the synthesis and self-assembly of carbohydrate-clicked rod-coil amphiphilic systems. Copper-catalyzed Huisgen cycloaddition was efficiently employed to functionalize the hydrophilic extremity of PEG-b-tetra(p-phenylene) conjugates by lactose and N-acetyl-glucosamine ligands. The resulting amphiphilic systems spontaneously self-assembled into nanoparticles when dissolved in aqueous media, as evidenced by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). The formation of highly monodisperse micelles having a mean diameter of 10 nm was observed for systems containing a PEG 900 core, and a decrease in the hydrophilic moiety (PEG 600) led to the formation of vesicles with a broader size distribution. The presence of carbohydrate residues on the surfaces of the micelles and their ability to establish specific interactions with wheat germ agglutinin (WGA) and peanut agglutinin (PNA) were further highlighted by light-scattering measurements, thus confirming the attractive applications of such sugar micelles in biosensor devices.