A Label-free, Highly Sensitive and Selective Detection of Hemin Based on the Competition between Hemin and Protoporphyrin IX Binding to G-Quadruplexes

作者：Kang, Bei Hua; Li, Na; Liu, Shi Gang; Li, Nian Bing; Luo, Hong Qun^*

来源：Analytical Sciences, 2016, 32(8): 887-892.

DOI：10.2116/analsci.32.887

• Fluorescence
• G-quadruplex
• protoporphyrin IX
• hemin detection

Herein is reported a simple and label-free fluorescent detection method for hemin based on using protoporphyrin IX (PPIX) as a fluorescent signal reporter. PPIX emits weak fluorescence in an aqueous solution. When PPIX binds to G-quadruplexes, the fluorescence intensity of PPIX is greatly increased. While in the presence of target hemin, hemin competes with PPIX toward G-quadruplexes because its affinity to G-quadruplexes is higher than that of PPIX. With the formation of the hemin-G-quadruplex complex, PPIX is released to the solution from the G-quadruplex accompanied by quenching of the fluorescence of the system. This fluorescence change of the system can be used to monitor hemin with a low detection limit of 36 nM. In addition, the possible binding sites for PPIX binding to the G-quadruplex are discussed based on competition between hemin and PPIX. What is more, this method might pave the way for applying G-quadruplexes and PPIX to more sensing systems.

• 出版日期2016-8
• 单位西南大学