梳型阳离子共聚物辅助构建DNA生物传感体系用于检测单碱基错配

A DNA Biosensing System Assisted by Comb-type Cationic Copolymer for the Detection of Single-base Mismatch

为了快速准确的检测出体系中单碱基错配,利用氧化石墨烯优异的荧光淬灭能力、对单双链DNA吸附能力的差异,搭配与之相配合出现较高的核酸伴侣活性的梳型阳离子共聚物PLL-g-Dex,构建了一个无酶、准确且高效的分析体系。通过荧光检测手段,首先确定了实验设计的可行性。之后依次检测过程中各组分的最优浓度,发现在T-DNA浓度为20 nmol/L的情况下,当GO浓度9μg/mL,cDNA浓度90 nmol/L,PLL-g-Dex浓度96 nmol/L时为最佳实验点。最后检测体系对单碱基错配的选择性,发现不同碱基错配体系所呈现出的荧光强度不同。而且相比其他碱基,PLL-g-Dex对C-C碱基错配的选择性较强。

In order to quickly and accurately detect the single-base mismatch in the system,using the difference of absorptivity between ssDNA and dsDNA and the excellent fluorescence quenching ability of the oxidized graphene,assorted with comb-type cationic copolymer PLLg-Dex that produces high nucleic acid companion activity while coordinated with the oxidized graphene,an enzyme-free,accurate and efficientanalysis system was established. First,the feasibility of experiment design was confirmed by fluorescence detection. Then in the detection ofoptimal concentration of every component in the process,it was found that the optimal experimental position occurred when the concentrationof T-DNA was 20 nmol/L,GO was 9μg/mL,cDNA was 90 nmol/L,and PLL-g-Dex was 96 nmol/L. Finally,the selectivity of the detectionsystem to single-base mismatch was collaborated,and the results revealed that the fluorescence intensities from different base mismatch systems differed. Moreover,compared to other bases,PLL-g-Dex presented stronger selectivity to C-C base mismatch.