Photoinduced electron transfer of DNA/Ag nanoclusters modulated by G-quadruplex/hemin complex for the construction of versatile biosensors.
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.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Libing
L
Zhang
Jinbo
J
Zhu
Shaojun
S
Guo
Tao
T
Li
Jing
J
Li
Erkang
E
Wang
D015374:Biosensing Techniques; D004247:DNA / Q000737:chemistry*; D004579:Electron Transport; D005456:Fluorescent Dyes / Q000737:chemistry; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
D005456:Fluorescent Dyes; D012834:Silver; D006427:Hemin; D004247:DNA