title: Cross-catalytic hairpin assembly-based exponential signal amplification for CRET assay with low background noise.
abstract: A toehold-mediated strand displacement (TMSD)-based cross-catalytic hairpin assembly (C-CHA) is demonstrated in this study, achieving exponential amplification of nucleic acids. Functionally, this system consists of four hairpins (H1, H2, H3 and H4) and one single-stranded initiator (I). Upon the introduction of I, the first CHA reaction (CHA1) is triggered, leading to the self-assembly of hybrid H1·H2 that then initiates the second CHA reaction (CHA2) to obtain the hybrid H3·H4. Since the single-stranded region in H3·H4 is identical to I, a new CHA1 is initiated, which thus achieves cross operation of CHA1 and CHA2 and exponential growth kinetics. Interestingly, because the C-CHA performs in a cascade manner, this system can be considered as multi-level molecular logic circuits with feedback mechanism. Moreover, through incorporating G-quadruplex subunits and fluorescein isothiocyanate (FITC) in the product of H1·H2, this C-CHA is readily utilized to fabricate a chemiluminescence resonance energy transfer (CRET) biosensing platform, achieving sensitive and selective detection of DNA and microRNA in real samples. Since the high background signal induced by FITC in the absence of initiator is greatly reduced through labeling quencher in H1, the signal-to-noise ratio and detection sensitivity are improved significantly. Therefore, our proposed C-CHA protocol holds a great potential for further applications in not only building complex autonomous systems but also the development of biosensing platforms and DNA nanotechnology.
authors.affiliation: Collaborative Innovation Center for Marine Biomass Fiber, Materials and Textiles of Shandong Province, College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Laboratory of Fiber Materials and Modern Textiles, the Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071, PR China.
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Yue
authors.affiliation: Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Collaborative Innovation Center for Marine Biomass Fiber, Materials and Textiles of Shandong Province, College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Laboratory of Fiber Materials and Modern Textiles, the Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071, PR China.
authors.forename: Hongjie
authors.initials: H
authors.lastname: Qi
authors.affiliation: Collaborative Innovation Center for Marine Biomass Fiber, Materials and Textiles of Shandong Province, College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Laboratory of Fiber Materials and Modern Textiles, the Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071, PR China.
authors.forename: Yongcun
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Collaborative Innovation Center for Marine Biomass Fiber, Materials and Textiles of Shandong Province, College of Chemistry and Chemical Engineering, Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials, Laboratory of Fiber Materials and Modern Textiles, the Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071, PR China. Electronic address: bisai11@126.com.
authors.forename: Sai
authors.initials: S
authors.lastname: Bi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002384:Catalysis; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D055029:Inverted Repeat Sequences / Q000235:genetics; D049449:Luminescence; D008163:Luminescent Measurements; D035683:MicroRNAs / Q000737:chemistry / Q000302:isolation & purification*; D036103:Nanotechnology / Q000379:methods*; D009690:Nucleic Acid Conformation
chemical_list: D035683:MicroRNAs; D004247:DNA
keywords: Chemiluminescence resonance energy transfer (CRET); Cross-catalytic hairpin assembly; Exponential signal amplification; Molecular logic circuits; Strand displacement reaction