An optical DNA logic gate based on strand-displacement and magnetic separation, with response to multiple microRNAs in cancer cell lysates
作者单位：Key Laboratory of Sensor Analysis of Tumor MarkerMinistry of EducationCollege of Chemistry and Molecular EngineeringQingdao University of Science and Technology
会议名称：《2017年中国肿瘤标志物学术大会暨第十一届肿瘤标志物青年科学家论坛》
会议日期：2017年
学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学]
关 键 词：Logic circuit Magnetic separation DNAzyme Spectrum Colorimetric
摘 要：A battery of logic gates, YES, AND and OR, are designed using magnetic beads(MBs) modified by DNA which consists of a substrate strand(S) and a signal strand on which the logic operates. Inputs stemming from micro-RNA(which represent three cancer biomarkers) take the place of signal DNA. The released signal strand self-assembles into the hemin-G-quadruplex complex(DNAzyme) that catalyzes a blue-green dye(ABTS+) from the precursor ABTS. This dye(quantified at a wavelength of 414 nm) represents the output signal for the various logic gates. The above-mentioned method allows for quantitative detection of microRNA of three kinds of logic gates in the range of 5 nM-500 nM with a detection limit of 3.8 nM, 4.9 nM, 5.4 nM. A Boolean logic circuitry is also achieved following the principles of multilevel strand displacement. Based on strand-displacement and magnetic separation, this work demonstrates the possibility of designing a logic system using micro-RNA in live cell lysate as inputs, in the hope of being potentially applied in DNA computation and cancer diagnosis.