Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Biosens Bioelectron. 2010 Oct 15;26(2):575-9. doi: 10.1016/j.bios.2010.07.034. Epub 2010 Jul 17.
A highly sensitive quartz crystal microbalance with dissipation monitoring (QCM-D) biosensor for protein was developed using aptamer-functionalized gold nanoparticles (Apt-GNPs) for amplification. Human α-thrombin, an important physiological protease found in blood, was chosen as the target protein. Captured by immobilized aptamers, thrombin was determined on-line using Apt-GNPs to enhance both frequency and dissipation signals. The fabricated sandwich of aptamer/thrombin/Apt-GNPs on chip surface was confirmed by atomic force microscopy (AFM). Compared to direct assay, the detection limit for thrombin was down to 0.1 nM, yielding about 2 orders of magnitude improvement in sensitivity. This aptamer-based QCM-D biosensor also showed good selectivity and repeatability in complex matrix. For the first time, the dual-signal enhancement of Apt-GNPs on QCM-D sensing was demonstrated, and such design could provide a promising detection strategy for proteins with two binding sites.
一种基于适配体功能化金纳米粒子（Apt-GNPs）放大的高灵敏度石英晶体微天平（QCM-D）生物传感器被开发出来，用于蛋白质检测。人凝血酶，一种在血液中发现的重要生理蛋白酶，被选为目标蛋白。通过固定化的适配体捕获，使用 Apt-GNPs 在线测定凝血酶，以增强频率和耗散信号。通过原子力显微镜（AFM）证实了芯片表面上的适配体/凝血酶/Apt-GNPs 三明治结构。与直接测定相比，凝血酶的检测限低至 0.1 nM，灵敏度提高了约 2 个数量级。该基于适配体的 QCM-D 生物传感器在复杂基质中也表现出良好的选择性和重复性。首次证明了 Apt-GNPs 在 QCM-D 传感中的双信号增强，这种设计可以为具有两个结合位点的蛋白质提供一种有前途的检测策略。
