Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764, South Korea.
Department of Materials Science and Engineering, Chungnam National University, Daejeon 305-764, South Korea; Department of Emerging Materials, Daegu Gyeongbuk Institute of Science and Technology, Daegu 711-873, South Korea.
Biosens Bioelectron. 2014 Sep 15;59:140-4. doi: 10.1016/j.bios.2014.03.021. Epub 2014 Mar 27.
The use of aptamer-based assays is an emerging and attractive approach in disease research and clinical diagnostics. A sensitive aptamer-based sandwich-type sensor is presented to detect human thrombin using a planar Hall magnetoresistive (PHR) sensor in cooperation with superparamagnetic labels. A PHR sensor has the great advantages of a high signal-to-noise ratio, a small offset voltage and linear response in the low-field region, allowing it to act as a high-resolution biosensor. In the system presented here, the sensor has an active area of 50 µm × 50 µm with a 10-nm gold layer deposited onto the sensor surface prior to the binding of thiolated DNA primary aptamer. A polydimethylsiloxane well of 600-µm radius and 1-mm height was prepared around the sensor surface to maintain the same specific area and volume for each sensor. The sensor response was traced in real time upon the addition of streptavidin-functionalized magnetic labels on the sensor. A linear response to the thrombin concentration in the range of 86 pM-8.6 µM and a lower detection limit down to 86 pM was achieved by the proposed present method with a sample volume consumption of 2 µl. The proposed aptasensor has a strong potential for application in clinical diagnosis.
基于适体的检测方法在疾病研究和临床诊断中是一种新兴且有吸引力的方法。本文提出了一种基于适体的灵敏三明治型传感器，该传感器采用平面霍尔磁阻（PHR）传感器与超顺磁标记物合作，用于检测人凝血酶。PHR 传感器具有高信噪比、小失调电压和低场区域线性响应等优点，使其能够作为高分辨率生物传感器。在本系统中，传感器的有效面积为 50 µm×50 µm，在传感器表面沉积了 10nm 的金层，然后再结合巯基化 DNA 一级适体。在传感器表面周围制备了 600 µm 半径和 1mm 高度的聚二甲基硅氧烷井，以保持每个传感器的相同比表面积和体积。在传感器上添加链霉亲和素功能化的磁性标记物后，实时跟踪传感器的响应。通过本方法可以在 86 pM-8.6 µM 的范围内得到线性响应，检测限低至 86 pM，样品体积消耗为 2 µl。所提出的适体传感器在临床诊断中有很大的应用潜力。
