A strategy for development of electrochemical DNA biosensor based on site-specific DNA cleavage of restriction endonuclease

作者：Chen, Jinghua; Zhang, Jing; Yang, Huanghao^*; Fu, Fengfu; Chen, Guonan

来源：Biosensors and Bioelectronics, 2010, 26(1): 144-148.

DOI：10.1016/j.bios.2010.05.033

• Electrochemical DNA Biosensor
• Site-specific DNA cleavage
• Restriction endonuclease
• Cymbidium mosaic virus

A new strategy for development of electrochemical DNA biosensor based on site-specific DNA cleavage of restriction endonuclease and using quantum dots as reporter was reported in this paper The biosensor was fabricated by immobilizing a capture hairpin probe, thiolated single strand DNA labeled with biotin group, on a gold electrode BfuCl nuclease, which is able to specifically cleave only double strand DNA but not single strand DNA, was used to reduce background current and Improve the sensitivity We demonstrated that the capture hairpin probe can be cleaved by BfuCl nuclease in the absence of target DNA, but cannot be cleaved in the presence of target DNA. The difference before and after enzymatic cleavage was then monitored by electrochemical method after the quantum dots were dissolved from the hybrids Our results suggested that the usage of BfuCl nuclease obviously Improved the sensitivity and selectivity of the biosensor. We successfully applied this method to the sequence-selective discrimination between perfectly matched and mismatched target DNA including a single-base mismatched target DNA, and detected as low as 3 3 x 10(-14) M of complementary target DNA Furthermore, our above strategy was also verified with fluorescent method by designing a fluorescent molecular beacon (MB), which combined the capture hairpin probe and a pair of fluorophore (TAMRA) and quenche

• 出版日期2010-9-15
• 单位福州大学; 福建医科大学