Hairpin assembly circuit-based fluorescence cooperative amplification strategy for enzyme-free and label-free detection of small molecule

Colorimetric biosensor using dual‐amplification of enzyme‐free reaction through universal hybridization chain reaction system

“…The hairpin design process was accomplished by considering a structure with a split G‐quadruplex sequence that showed high signal‐to‐background when referring to the previously reported study. (Feng et al, ). The structure of the hairpin was on the basis of condition 1: UH1 was designed so that the G‐quadruplex sequence in the hairpin was split at both ends and that one‐third of the entire sequence was blocked in the stem.…”

“…Therefore, non‐PCR‐based signal amplification strategies have been developed to match conditions suitable for the field detection; rolling circle amplification (Liu et al, ), nucleic acid sequence‐based amplification (Compton ), loop‐mediated isothermal amplification (Notomi et al, ), and hybridization chain reaction (HCR; Dirks & Pierce, ). Also, in recent years, fusion strategies of these non‐PCR‐based signal amplification strategies have been developed (Feng et al, ; Li et al, ; Song et al, ).…”

“…Recently developed G‐quadruplex‐based HCR system was able to detect nucleic acid by constructing a hairpin set with a non‐split G‐quadruplex sequence in a closed stem and loop (Dong et al, ). Furthermore, a comparative experiment on hairpin sets with differently split G‐quadruplex structure in HCR could find the structure that can obtain the maximum signal to improve the performance of the system (Feng et al, ). Despite the many advantages of the developed strategies, they still have the inconvenience of redesigning the hairpin set according to the sequence of the target each time.…”

Coupling hybridization chain reaction with catalytic hairpin assembly enables non-enzymatic and sensitive fluorescent detection of microRNA cancer biomarkers

“…HCR, first reported by Pierce and colleagues (Dirks and Pierce, 2004;Choi et al, 2010), involves the assembly of two hairpin DNAs into long dsDNA polymers by the DNA triggers, while the CHA relies on catalytic assembly two hairpin DNAs into dsDNA strands with cyclic reuse of the DNA triggers (Jiang et al, 2014;Song et al, 2015). Both HCR and CHA can take place isothermally without the involvement of any enzyme and have shown significant signal amplification capabilities for detecting various nucleic acid targets (Feng et al, 2015;Milligan and Ellington, 2015). The integration of HCR and CHA thus enables us to detect miR-141 at sub-femtomolar level in an enzyme-free and dual amplified fashion.…”

Strand-Exchange Nucleic Acid Circuitry with Enhanced Thermo-and Structure- Buffering Abilities Turns Gene Diagnostics Ultra-Reliable and Environmental Compatible

“…Due to the high signal-to-background ratio and programmability, CHA has been widely applied into detecting various analytical platforms and considered as a new generation of signal amplifier and transducer. A wide range of targets have been designed as catalysts for detection, including oligonucleotides1011, aptamer-intermediated non-nucleic acid species such as proteins and small molecules1213, nucleic acid nanostructures14, and certain isothermal nucleic acid amplification products such as rolling circle amplification (RCA) and strand exchange amplification (SDA)1516.…”