【摘要】 采用基于密度泛函理论的LDA(PWC)方法对比研究了纯单壁纳米碳管(SWCNT)和B掺杂单壁碳纳米管(B doped SWCNT)表面吸附DNA碱基(腺嘌呤)A、(胸腺嘧啶)T、(胞嘧啶)C、(鸟嘌呤)G的吸附特性和本质,计算研究了最佳吸附位点,吸附能,以及稳定吸附模型的电子结构.结果表明掺杂元素B的引入不会造成SWCNT的结构畸变,可以局部影响碳纳米管的电子结构,有效增强SWCNT与DNA碱基之间的电子相互作用,DNA碱基以化学吸附的形式修饰在B掺杂SWCNT的表面.研究结果预示B掺杂SWCNT表面修饰DNA碱基有潜力成为DNA生物传感器生物识别界面的主要成分.更多还原

【Abstract】 A comparative study was conducted to assess the adsorption and characteristics of the four types of DNA bases, A, T, C, and G, on pristine and B-doped SWCNTs by density functional theory calculations with LDA(PWC) method. The configurations of the best sites, the adsorption energies in the best sites and the electronic structures of stable adsorption models, including DOS, PDOS, electron density map, mulliken charge properties of DNA bases and B atom before and after adsorption on pristine and B-doped SWCNTs have been investigated. And the frontier orbital energy gap and charge transfer of DNA bases adsorption on pristine and B-doped SWCNTs have been also investigated. The results indicated that the best adsorption site of DNA base adsorption on pristine and B-doped SWCNTs was on the top of carbon and B atoms. The bases A, G were adsorbed on pure SWCNT by weak interaction, the bases T, C were adsorbed on pure SWCNT by strong chemical interaction. The bases A, T, C, G were adsorbed on B-doped SWCNT by chemical interaction. After B doping, the structure of the SWCNT was not distorted, however, the local electronic structure was modified. The frontier orbital energy gap of SWCNT could be effectively reduced by B doping. Moreover, the electronic reactivity with the DNA bases of SWCNT were enhanced by B doping. The DNA bases on the surface of B-doped SWCNT could be modified by Chemical adsorption. This method for the modification of DNA bases on B-doped SWCNT surface has great potential for the construction of DNA biosensors of biorecognition interfaces.更多还原