Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, College of Chemistry and Life Sciences , Zhejiang Normal University , Jinhua , Zhejiang 321004 , China.
Anal Chem. 2018 Nov 20;90(22):13183-13187. doi: 10.1021/acs.analchem.8b04070. Epub 2018 Nov 1.
Relative to the individual intensity-dependent strategy, the multicolor fluorescence sensor has promise to achieve a high signaling contrast. In this work, we develop a cucurbituril-based supramolecular and multicolor DNA recognition rationale via indicator competition assay (ICA). Alkaloids of coptisine (COP) and palmatine (PAL) are identified as the proof-of-principle indicators with a lighting-up fluorescence upon supramolecular complexation to cucurbit[7]uril (CB[7]). With an introduced abasic site (AP site) as the contestant, DNAs having pyrimidines opposite this site can compete for COP with CB[7] to bring an emission color change from green to yellow brown, while those having purines opposite the AP site do not compete for COP and still have the green emission, indicative of a high selectivity for the multicolor nucleotide transversion recognition. However, because of the relatively weaker binding of PAL with CB[7], the AP site-containing DNA can take away PAL from its CB[7] complex and resultantly bring a blue-to-green emission color change independent of the AP site-opposite nucleotide identity, dissimilar to the remaining blue color for the fully matched DNA without the AP site, suggesting a preferable strategy for the AP site biomarker detection. Our method demonstrates a new way to develop an ICA-based multicolor DNA sensor with the supramolecular cucurbituril complexation to ensure a highly selective performance.
与个体强度依赖策略相比，多色荧光传感器有望实现高信号对比度。在这项工作中，我们通过指示剂竞争测定法（ICA）开发了一种基于葫芦[7]脲的超分子和多色 DNA 识别原理。小檗碱（COP）和巴马汀（PAL）生物碱被确定为原理验证指示剂，它们在与葫芦[7]脲（CB[7]）超分子络合时会发出点亮的荧光。引入无碱基位点（AP 位点）作为竞争者，在该位点具有嘧啶的 DNA 可以与 CB[7]竞争 COP，从而使发射颜色从绿色变为黄棕色，而在 AP 位点具有嘌呤的 DNA 则不会与 COP 竞争，并且仍然具有绿色发射，表明对多色核苷酸转换识别具有高选择性。然而，由于 PAL 与 CB[7]的结合较弱，含 AP 位点的 DNA 可以从其 CB[7]复合物中夺走 PAL，从而导致独立于 AP 位点对面核苷酸身份的蓝绿色发射颜色变化，与不含 AP 位点的完全匹配 DNA 的其余蓝色不同，这表明该方法是 AP 位点生物标志物检测的较好策略。我们的方法展示了一种基于 ICA 的多色 DNA 传感器的新方法，该传感器基于超分子葫芦[7]脲络合，以确保具有高度选择性的性能。
