A universal platform for sensitive and selective colorimetric DNA detection based on Exo III assisted signal amplification.
Rapid growth of available sequence data has made the detection of nucleic acids critical to the development of modern life sciences. Many amplification methods based on gold nanoparticles and endonuclease for sensitive DNA detection have been developed. However, these approaches require specific target sequence for endonuclease recognition, which cannot be fulfilled in all systems. Replacing the restriction enzyme with a nuclease that does not require any specific recognition sequence may offer a universally adaptable system. Here we have developed a novel homogeneous, colorimetric DNA detection method, which consists of Exo III, a linker DNA, and two DNA-modified gold nanoparticles. This system is simple, low-cost, sensitive and selective. By coupling cyclic enzymatic cleavage and gold nanoparticle for signal amplification, our system provides a colorimetric detection limit of 15 pM, which is 3 orders of magnitude more sensitive than that of a general three-component sandwich assay format. Due to the intrinsic property of Exo III, our method shows excellent detection selectivity for single-base discrimination. More importantly, superior to other methods based on nicking and FokI endonuclease, our target sequence-independent platform is generally applicable for DNA sensing. This new approach could be widely applied to sensitive nucleic acids detection.
College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, China.
Liang
L
Cui
Guoliang
G
Ke
Wei Yun
WY
Zhang
Chaoyong James
CJ
Yang
D015374:Biosensing Techniques / Q000295:instrumentation*; D003124:Colorimetry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005090:Exodeoxyribonucleases / Q000737:chemistry*; D021141:Nucleic Acid Amplification Techniques / Q000295:instrumentation*; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
D004247:DNA; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III