School of Chemical Engineering, Sungkyunkwan University, Suwon, 440-746, Korea.
Analyst. 2012 Mar 7;137(5):1241-6. doi: 10.1039/c2an15900g. Epub 2012 Jan 19.
Polydiacetylene (PDA) liposomes possess unique properties that allow liposomes to change color and emit fluorescence in response to stimuli such as temperature, antibody-antigen interaction, pH, mechanical stress, and organic solvent. They have been studied extensively as signal transducers in biosensor applications. Here, we describe an antibody-based biosensor using PDA liposomes for detection of human immunoglobulin E (hIgE). Target hIgE chemically bound to hIgE monoclonal antibodies immobilized on PDA liposomes and the fluorescent signals were slightly increased depending on the target protein concentration. As the primary response, the hIgE could be detected to below 10 ng mL(-1). However, fluorescent signals were dramatically increased depending on the target protein concentration when gold nanoparticle-conjugated polyclonal antibody probes were added on the PDA liposomes after the primary immune reaction. A PDA liposome biosensor could detect the hIgE as low as 0.1 ng mL(-1) and the sensitivity was increased up to one hundred times higher than the primary response. As a result, we confirmed that gold nanoparticle-conjugated polyclonal antibody probes efficiently enhanced the fluorescent signal of the PDA liposome biosensor chip. This strategy can be useful to detect proteins of ultra-low concentration.
聚二乙炔（PDA）脂质体具有独特的性质，能够在温度、抗体-抗原相互作用、pH 值、机械应力和有机溶剂等刺激下改变颜色并发出荧光。它们已被广泛研究作为生物传感器应用中的信号转导器。在这里，我们描述了一种基于抗体的生物传感器，该传感器使用 PDA 脂质体来检测人免疫球蛋白 E（hIgE）。目标 hIgE 通过化学结合到固定在 PDA 脂质体上的 hIgE 单克隆抗体上，并且荧光信号根据目标蛋白浓度略有增加。作为初步反应，可以检测到低于 10ng mL(-1)的 hIgE。然而，当在初级免疫反应后将金纳米粒子缀合的多克隆抗体探针添加到 PDA 脂质体上时，荧光信号根据目标蛋白浓度显著增加。PDA 脂质体生物传感器可以检测到低至 0.1ng mL(-1)的 hIgE，灵敏度比初级反应提高了 100 倍以上。结果证实，金纳米粒子缀合的多克隆抗体探针可以有效地增强 PDA 脂质体生物传感器芯片的荧光信号。这种策略可用于检测超低浓度的蛋白质。
