Stanford Genome Technology Center, Stanford University, 855 California Ave, Palo Alto, CA 94304, USA.
Biosens Bioelectron. 2010 Mar 15;25(7):1635-9. doi: 10.1016/j.bios.2009.11.028. Epub 2009 Dec 5.
Rapid and multiplexed measurement is vital in the detection of food-borne pathogens. While highly specific and sensitive, traditional immunochemical assays such as enzyme-linked immunosorbent assays (ELISAs) often require expensive read-out equipment (e.g. fluorescent labels) and lack the capability of multiplex detection. By combining the superior specificity of immunoassays with the sensitivity and simplicity of magnetic detection, we have developed a novel multiplex magnetic nanotag-based detection platform for mycotoxins that functions on a sub-picomolar concentration level. Unlike fluorescent labels, magnetic nanotags (MNTs) can be detected with inexpensive giant magnetoresistive (GMR) sensors such as spin-valve sensors. In the system presented here, each spin-valve sensor has an active area of 90 microm x 90 microm, arranged in an 8 x 8 array. Sample is added to the antibody-immobilized sensor array prior to the addition of the biotinylated detection antibody. The sensor response is recorded in real time upon the addition of streptavidin-linked MNTs on the chip. Here we demonstrate the simultaneous detection of multiple mycotoxins (aflatoxins B(1), zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved.
快速且多重检测在食源性病原体检测中至关重要。虽然传统的免疫化学分析方法（如酶联免疫吸附测定（ELISA））具有高度特异性和敏感性，但往往需要昂贵的读出设备（例如荧光标记物），并且缺乏多重检测的能力。通过将免疫分析的优异特异性与磁性检测的灵敏度和简单性相结合，我们开发了一种新型的基于磁性纳米标签的多重检测平台，用于检测真菌毒素，其检测灵敏度可达亚皮摩尔浓度水平。与荧光标记物不同，磁性纳米标签（MNTs）可以使用廉价的巨磁电阻（GMR）传感器（如自旋阀传感器）进行检测。在本系统中，每个自旋阀传感器的有效面积为 90 微米 x 90 微米，呈 8 x 8 阵列排列。在加入生物素化检测抗体之前，将样品添加到抗体固定化传感器阵列中。在芯片上加入链霉亲和素连接的 MNTs 后，实时记录传感器响应。在这里，我们演示了对多种真菌毒素（黄曲霉毒素 B(1)、玉米赤霉烯酮和 HT-2）的同时检测，并表明可以达到 50 pg/mL 的检测限。
