title: Binding-induced and label-free colorimetric method for protein detection based on autonomous assembly of hemin/G-quadruplex DNAzyme amplification strategy.
abstract: In this work, a new binding-induced and label-free colorimetric method for protein detection has been developed on the basis of an autonomous assembly of hemin/G-quadruplex DNAzyme amplification strategy. The system consists of two proximity probes carrying two aptamer sequences as recognition elements for target, and two hairpin structures include three-fourths and one-fourth of the G-quadruplex sequences in inactive configuration as functional elements. In the presence of target protein, two proximity probes bind to the protein simultaneously, forming a stable DNA-protein complex. Then the complex triggers an autonomous cross-opening of the two functional hairpin structures, leading to the formation of numerous hemin/G-quadruplex DNAzymes. The resulting DNAzymes catalyze the oxidation of colorless 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(2-)) to the green-colored ABTS(•-) with the presence of H2O2, thus providing the amplified colorimetric detection of target. Using human α-thrombin as the protein target, this binding-induced DNAzyme amplification colorimetric method affords high sensitivity with a detection limit of 1.9 pM. Furthermore, this method might be further extended to sensitive detection of other proteins by simply replacing recognition elements of proximity probes.
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China. Electronic address: wuhao@jsinm.org.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China.
authors.forename: Yaling
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China.
authors.forename: Hongyong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China.
authors.forename: Feifan
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine. Wuxi, Jiangsu 214063, China. Electronic address: zoupei@jsinm.org.
authors.forename: Pei
authors.initials: P
authors.lastname: Zou
mesh_terms: D001665:Binding Sites; D015374:Biosensing Techniques / Q000295:instrumentation*; D003124:Colorimetry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation*; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000295:instrumentation*; D013194:Staining and Labeling; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry / Q000235:genetics
chemical_list: D006427:Hemin; D013917:Thrombin
keywords: Autonomous assembly; Binding-induced; Colorimetric; DNAzyme amplification; Human α-thrombin