Real-time monitoring of enzyme-free strand displacement cascades by colorimetric assays.
The enzyme-free toehold-mediated strand displacement reaction has shown potential for building programmable DNA circuits, biosensors, molecular machines and chemical reaction networks. Here we report a simple colorimetric method using gold nanoparticles as signal generators for the real-time detection of the product of the strand displacement cascade. During the process the assembled gold nanoparticles can be separated, resulting in a color change of the solution. This assay can also be applied in complex mixtures, fetal bovine serum, and to detect single-base mismatches. These results suggest that this method could be of general utility to monitor more complex enzyme-free strand displacement reaction-based programmable systems or for further low-cost diagnostic applications.
Key Laboratory for Large-Format Battery Materials and Systems, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), Wuhan, China. xiafan@hust.edu.cn.
Ruixue
R
Duan
Boya
B
Wang
Fan
F
Hong
Tianchi
T
Zhang
Yongmei
Y
Jia
Jiayu
J
Huang
Abdul
A
Hakeem
Nannan
N
Liu
Xiaoding
X
Lou
Fan
F
Xia
D020137:Base Pair Mismatch / Q000235:genetics; D001483:Base Sequence; D003124:Colorimetry / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry* / Q000235:genetics*; D004798:Enzymes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
D004798:Enzymes; D006046:Gold; D004247:DNA