Ingebrandt S, Han Y, Nakamura F, Poghossian A, Schöning M J, Offenhäusser A
Institute of Bio- and Nanosystems, Institute 2: Bioelectronics, Center of Nanoelectronic Systems for Information Technology, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
Biosens Bioelectron. 2007 Jun 15;22(12):2834-40. doi: 10.1016/j.bios.2006.11.019. Epub 2006 Dec 21.
We present a label-free method for the detection of DNA hybridization, which is monitored by non-metallized silicon field-effect transistors (FET) in a microarray approach. The described method enables a fast and fully electronic readout of ex situ binding assays. The label-free detection utilizing the field-effect is based on the intrinsic charge of the DNA molecules and/or on changes of the solid-liquid interface impedance, when biomolecules bind to the sensor surface. With our sensor system, usually a time-resolved, dc readout is used. In general, this FET signal suffers from sensor drift, temperature drift, changes in electrolyte composition or pH value, influence of the reference electrode, etc. In this article, we present a differential ac readout concept for FET microarrays, which enables a stable operation of the sensor against many of these side-parameters, reliable readout and a possibility for a quick screening of large sensor arrays. We present the detection of point mutations in short DNA samples with this method in an ex situ binding assay.
我们提出了一种用于检测DNA杂交的无标记方法，该方法通过微阵列方法中的非金属化硅场效应晶体管（FET）进行监测。所描述的方法能够对异位结合测定进行快速且完全电子化的读出。利用场效应的无标记检测基于DNA分子的固有电荷和/或生物分子与传感器表面结合时固液界面阻抗的变化。对于我们的传感器系统，通常使用时间分辨的直流读出。一般来说，这种FET信号会受到传感器漂移、温度漂移、电解质成分或pH值变化、参比电极影响等因素的干扰。在本文中，我们提出了一种用于FET微阵列的差分交流读出概念，该概念能够使传感器针对许多这些次要参数实现稳定运行、可靠读出，并有可能对大型传感器阵列进行快速筛选。我们用这种方法在异位结合测定中检测了短DNA样品中的点突变。
