Abasic site-switched structure conversion of neutral red for selective DNA recognition
Abasic site-switched structure conversion of neutral red for selective DNA recognition
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DOI：
10.1016/j.snb.2013.07.034
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发表时间：
2013-11
影响因子：
8.4
通讯作者：
Yanwei Sun;Yong Shao;Jian Peng;Lingling Liu;Botao Teng
中科院分区：
文献类型：
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作者：
Yanwei Sun;Yong Shao;Jian Peng;Lingling Liu;Botao Teng
小分子结构和性质的DNA结合开关转换为实现DNA特定位点的高选择性鉴定提供了一种很有前途的工具。为此，我们研究了中性红与其碱性位(AP位)结合后的光学性质。在pH为8.4时，中性红在溶液中主要以中性形式存在。然而，DNA中AP位的存在会将NR转化为质子化形式(NRH+)，吸收光谱发生了100 nm的红移。这种转换对于没有AP位点的完全匹配的DNA来说是低效的。相对于吸收光谱，荧光对结合开关转换的响应更依赖于AP位点附近的序列。AP位的疏水微环境和激发态AP位结合的NRH+与附近的上下文碱基之间的电子转移控制着发射行为。研究发现，具有较大空穴空间的AP位有利于结合的NRH+与上下文碱基之间发生偶极相互作用。这种AP对中性红的结构和光学性质的依赖于位置的转化，将在DNA分析领域以高选择性和高灵敏度得到广泛的应用。
DNA-binding-switched conversion of small molecule's structure and property provides a promising tool for achieving a high selectivity in identification of a DNA specific site. Herein, the optical properties of neutral red in response to its abasic site (AP site) binding were investigated for this purpose. At pH 8.4, neutral red exists in solution mainly at the neutral form (NR). However, the presence of an AP site in DNA converts NR to a protonated form (NRH+), following a 100-nm red shift in absorption spectra. This conversion is inefficient for the fully matched DNAs without the AP site. Relative to the absorption spectra, the fluorescence in response to the binding-switched conversion is more dependent on the sequences near the AP site. The AP site's hydrophobic microenvironment and electron transfer between the AP site-bound NRH+in excited state and the nearby context bases govern the emission behavior. It was found that the AP site having a large void space favors occurrence of dipole interaction between the bound NRH+and the context bases. This AP site-dependent conversion of neutral red in structure and then its optical properties would find wide applications in the field of DNA assay with a high selectivity and sensitivity.