基于自组装磁珠光电检测到DNA计算研究

DNA analysis technology has been focused by many scientists recent years because of enormous information generated in the Human Genome Project. The realization requires faster, simpler, and cheaper manners to detect genetic information. Most early DNA hybridization detection relied on optical transduction experiment devices. But this method is hampered by the need for bulky and costly control instrumentation，and then more label-free tools are invented to instead of expensive fluorescent detection system. With the development of micro electric technology, DNA electric sensors and high-density DNA arrays become true and play a key role in DNA analysis technology. The essential of DNA electrical detection is the conversion of the Watson-Crick base-pair recognition into electrical signal. Recently, another new manner namedphotoelectricity technology has been more and more concerned by DNA detection fields, which uses highly sensitive and cheap photodiodes as signal transducer, depends on the conversion of light intensity change generated by hybridization into useful electric signal, and then integrated with electric computer to construct a fully automatic DNA detection system. In this paper, we have designed a new photoelectric DNA detection platform with magnetic beads, Ordinary optical illumination is used as light device. DNA probes are immobilized on the detection platform, magnetic beads labeling form a opaque area above the surface of platform after DNA targets hybridization, and then bottom-photodiode structure detects light intensity change with electronic readout, hybridization signal can be recognized quickly by program controlled electronic computer. This detection platform also fits for DNA computing because magnetic property could easily eliminate unfeasible solutions of problem, which provides a new idea to construct a fully automatic DNA computer with photoelectric readout.

由于人类基因工程产生的大规模基因信息需求，DNA检测技术近年来成为科学家们的关注焦点。现实迫切需要更加快速、简便和低成本的DNA序列以及DAN分子特异性杂交等的检测工具及方法。大多数早期的DNA杂交检测技术主要利用光学显微镜等实验仪器设备。但是这项技术的发展由于检测仪器体积庞大，成本昂贵受到了严重的限制，因此逐渐被越来越多简便、低成本的检测技术替代。 本文提出了一种新型的DNA光电检测平台，原理是利用可见光信号强弱的变化检测DNA杂交信号。系统中的检测平台同样是由兼容探针DNA自组装的硅集成电路构成。而在此系统中目标DNA序列和磁珠连接，目标DNA序列与探针DNA分子杂交后，磁珠就会覆盖在载体表面形成暗区。而载体下方的光电二极管阵列此时便可以检测出DNA杂交反应前后的光信号变化，由此输出DNA杂交信号。该系统为研制可程序化、自动化的DNA计算机提供了新思路。

本项目设计出了一种新型的DNA光电检测平台，利用可见光信号强弱的变化检测DNA杂交信号。完成了系统的检测平台设计，该平台由兼容探针DNA自组装的硅集成电路构成。系统中目标DNA序列与磁珠连接，目标DNA序列与探针DNA分子杂交后，磁珠就会覆盖在载体表面形成暗区。载体下方的光电二极管阵列此时便可以检测出DNA杂交反应前后的光信号变化，输出DNA杂交信号。