Kim Jun Pyo, Park Cheol Hee, Sim Sang Jun
Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, South Korea.
J Nanosci Nanotechnol. 2011 May;11(5):4269-74. doi: 10.1166/jnn.2011.3664.
In this study, we demonstrate an aptamer-based biosensor (apta-biosensor) using PDA liposomes for label-free detection of allergy diagnosis by hIgE detection. In order to detect the target hIgE, the surface of PDA liposome were functionalized with hIgE antibody and anti-hIgE aptamer as a receptor, and the target hIgE onto the receptors was detected by the change of fluorescence signal. The hIgE antibody-modified PDA liposome biosensor had a serious problem that the immune reaction between receptor and target could not powerfully affect the change of florescence signal on PDA liposome. In order to solve this problem, the anti-hIgE aptamer which was far smaller than whole antibody was introduced as the receptor for the PDA liposome system. An aptamer-based PDA liposome biosensor was able to measure a quantity of target protein with various concentrations and at this time the detection limit was 141 ng/mL of the hIgE concentration. These results enabled diagnosis of allergy disease by an aptamer-based PDA liposome biosensor because real allergic patients showed high concentration of hIgE in serum (greater than 290 ng/mL). Therefore, we suggest that aptamer-modified PDA supramolecules as promising candidates for development of label-free colorimetric biosensors.
在本研究中，我们展示了一种基于适配体的生物传感器（适配体生物传感器），它使用聚多巴胺脂质体通过检测人免疫球蛋白E（hIgE）进行无标记的过敏诊断检测。为了检测目标hIgE，聚多巴胺脂质体表面用hIgE抗体和抗hIgE适配体作为受体进行功能化修饰，通过荧光信号的变化来检测受体上的目标hIgE。hIgE抗体修饰的聚多巴胺脂质体生物传感器存在一个严重问题，即受体与目标之间的免疫反应无法有力地影响聚多巴胺脂质体上荧光信号的变化。为了解决这个问题，引入了比完整抗体小得多的抗hIgE适配体作为聚多巴胺脂质体系统的受体。基于适配体的聚多巴胺脂质体生物传感器能够测量不同浓度的目标蛋白，此时hIgE浓度的检测限为141 ng/mL。这些结果使得基于适配体的聚多巴胺脂质体生物传感器能够诊断过敏疾病，因为真正的过敏患者血清中hIgE浓度较高（大于290 ng/mL）。因此，我们认为适配体修饰的聚多巴胺超分子有望成为开发无标记比色生物传感器的候选材料。
