An aptasensor was designed for sensitive detection of thrombin using in biological fluids by integrating a magnetic aptamer-microbeads. To achieve this goal, the surface of gold plated QCM crystals was coated with L-cysteine and a thrombin binding DNA aptamer was immobilized on the L-cysteine coated QCM crystals surface via glutaraldehyde coupling. The binding interactions of thrombin to QCM crystals were characterized. Magnetic poly(2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate-vinylene carbonate), Mp(HEMA-EGDMA-VC) microbeads were synthesized and thrombin binding aptamer (TBA) was immobilized. The Mp(HEMA-EGDMA-VC)-TBA microbeads were effectively adsorbed thrombin from serum in a relatively short contact time (ca. 5.0 min), and the eluted protein from Mp(HEMA-EGDMA-VC)-TBA was transferred to the QCM aptasensor that showed a specific detection of thrombin from serum. The detection limit of thrombin using aptasensor was 1.00 nmol L⁻¹. The calculation dissociation constant of the aptasensor was 68.5 nmol L⁻¹. The selectivity of the aptasensor system was tested with three different proteins (i.e., elastin, immunoglobulin G (IgG) and human serum albumin (HSA)) and showed high specificity to thrombin. The aptasensor was regenerated by washing with NaOH solution, and repeatedly used until 20 cycles without a change in the performance.

通过整合磁性适体-微珠，设计了一种适体传感器，用于在生物流体中灵敏地检测凝血酶。为了实现这个目标，在镀金的QCM晶体表面涂上了L-半胱氨酸，并在L上固定了凝血酶结合DNA适体。-半胱氨酸包被的QCM晶体通过戊二醛偶联作用形成表面。表征了凝血酶与QCM晶体的结合相互作用。合成了磁性聚（甲基丙烯酸2-羟乙酯-乙二醇二甲基丙烯酸酯-碳酸亚乙烯酯），Mp（HEMA-EGDMA-VC）微珠，并固定了凝血酶结合适体（TBA）。Mp（HEMA-EGDMA-VC）-TBA微珠在相对较短的接触时间（约5.0分钟）内有效吸附了血清中的凝血酶，并将Mp（HEMA-EGDMA-VC）-TBA洗脱的蛋白质转移至QCM适体传感器，可特异性检测血清中的凝血酶。使用适体传感器的凝血酶的检出限为1.00 nmol L ^-1。适体传感器的计算解离常数为68.5 nmol L ^-1。用三种不同的蛋白质（即弹性蛋白，免疫球蛋白G（IgG）和人血清白蛋白（HSA））测试了适体传感器系统的选择性，并显示出对凝血酶的高度特异性。通过用NaOH溶液洗涤来再生适体传感器，并重复使用直到20个循环而性能没有改变。