Photoinduced Electron Transfer of DNA/Ag Nanoclusters Modulated by G-Quadruplex/Hemin Complex for the Construction of Versatile Biosensors

作者：Libing Zhang, Jinbo Zhu, Shaojun Guo, Tao Li, Jing Li, Erkang Wang · 发表于：Journal of the American Chemical Society · 年份：2013 · DOI：10.1021/ja3089857 · 被引用次数：279 · 研究领域：Advanced biosensing and bioanalysis techniques、Nanocluster Synthesis and Applications、DNA and Nucleic Acid Chemistry

Photoinduced electron transfer (PET) has been observed for the first time between DNA/Ag fluorescent nanoclusters (NCs) and G-quadruplex/hemin complexes, accompanied by a decrease in the fluorescence of the DNA/Ag NCs. In this PET process, a parallel G-quadruplex and the sensing sequences are blocked by a duplex. The specific combination of targets with the sensing sequence triggers the release of the G-quadruplex and allows it to fold properly and bind hemin to form a stable G-quadruplex/hemin complex. The complex proves favorable for PET because it makes the G-quadruplex bind hemin tightly, which promotes the electron transfer from the DNA/Ag NCs to the hemin Fe(III) center, thus resulting in a decrease in the fluorescence intensity of the DNA/Ag NCs. This novel PET system enables the specific and versatile detection of target biomolecules such as DNA and ATP with high sensitivity based on the choices of different target sequences.