An isothermal strand displacement amplification strategy for nucleic acids using junction forming probes and colorimetric detection

作者：Wang, Xuchu^*; Liu, Weiwei; Yin, Binbin; Sang, Yiwen; Liu, Zhenping; Dai, Yu; Duan, Xiuzhi; Zhang, Gong; Ding, Shijia; Tao, Zhihua

来源：Microchimica Acta, 2017, 184(6): 1603-1610.

DOI：10.1007/s00604-017-2158-7

• Three way junction
• Strand displacement
• Colorimetric detection
• Isothermal amplification

The authors describe a method for DNA target recognition and signal amplification that is based on the target-induced formation of a three way junction. The subsequent assembly of two DNA probes releases the inhibitory strand and triggers a downstream strand displacement amplification. This causes the formation of a G-rich single sequence that binds to a hemin monomer with its peroxidase-mimicking properties. The resulting peroxidase (POx) activity is quantified by using H2O2 and TMB as the substrate. In the presence of an inhibitor, in contrast, the POx-like activity is strongly reduced. This forms the basis for a highly sensitive DNA assay. It has a 0.8 pM detection limit when operated at a wavelength of 450 nm and was applied to the isothermal determination of target DNA with high selectivity.

• 出版日期2017-6
• 单位重庆医科大学; 浙江大学