石墨烯基生物分子传感器件的第一性原理研究

First-Principles Study of Graphene-Based Biomolecular Sensor

基于第一性原理模拟,我们构建了一种具有石墨烯电极的纳米间隙生物分子传感器件的理论模型,研究发现,当碱基分子胞嘧啶、甲基化胞嘧啶和羟甲基化胞嘧啶分别通过器件时,器件横向电流的大小差异约有1个数量级,器件对此类分子具有一定的分辨能力.分子之间的区分度大小受单链脱氧核糖核酸(DNA)中相邻碱基分子间的相互作用及碱基分子构型的影响.研究工作表明,此类石墨烯基分子传感器可准确高效地区分具有不同结构的碱基分子,为准确定位DNA链中的变异碱基分子提岀了一种新的思路.

First-principles calculations were applied to design and study the electron transport behavior of a biomolecular sensor with graphene-based electrodes. It is shown that the designed biosensor is capable of distinguishing different nucleotide molecules such as cytosine, methylcytosine, and hydroxymethylcytosine. The current was seen to change by nearly one order of magnitude, while molecules passed through the device individually. The resolution capacity of the present device was primarily determined by the interactions and specific configurations of two adjacent single-stranded desoxyribonucleic acid （DNA） molecules and their specific configurations. This graphene-based biosensor was proved to be effective and efficient in detecting and distinguishing different DNA molecules, which provides a new potential method to pinpoint exactly varietal base molecules in DNA chains for the genetic information.