Miyazawa Yuuya, Sakata Toshiya
Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Eur Biophys J. 2014 May;43(4-5):217-25. doi: 10.1007/s00249-014-0948-y. Epub 2014 Mar 5.
In this article, we report a novel method of biomolecular recognition based on the molecular charge contact (MCC). As one of the MCC biosensing method, the interaction between DNA-coated magnetic beads and a silicon-based semiconductor, an ion-sensitive field effect transistor (ISFET) could be detected for DNA molecular recognition events using the principle of the field effect, which enables detecting ionic or molecular charges. After DNA-coated magnetic beads had been introduced and brought in contact with the gate surface by a magnet, the threshold voltage of the ISFET was shifted in the positive direction by immobilization, hybridization and extension reaction of DNA molecules on magnetic beads. This positive shift was based on the increase in negative charges of the phosphate groups in them. Then, the ISFET device could be reused a couple of dozen times continuously and cost-effectively because the oligonucleotide probes were tethered to the magnetic beads, but this was not done directly on the gate surface of the ISFET. Moreover, the MCC biosensing method enabled discrimination of a single nucleotide polymorphism. By creating an interaction of magnetic beads with the semiconductor, we can expect enhancement of the reaction efficiency in a solution and reuse of the device by separating the reaction field from the sensing substrate.
在本文中，我们报道了一种基于分子电荷接触（MCC）的新型生物分子识别方法。作为MCC生物传感方法之一，利用场效应原理，可检测涂有DNA的磁珠与硅基半导体（离子敏感场效应晶体管，ISFET）之间的相互作用，以实现DNA分子识别事件的检测，该原理能够检测离子或分子电荷。在引入涂有DNA的磁珠并通过磁铁使其与栅极表面接触后，由于磁珠上DNA分子的固定、杂交和延伸反应，ISFET的阈值电压正向偏移。这种正向偏移是基于其中磷酸基团负电荷的增加。然后，由于寡核苷酸探针连接在磁珠上，而非直接连接在ISFET的栅极表面，因此ISFET器件可以连续几十次经济高效地重复使用。此外，MCC生物传感方法能够区分单核苷酸多态性。通过创建磁珠与半导体之间的相互作用，我们有望提高溶液中的反应效率，并通过将反应场与传感基板分离来实现器件的重复使用。
