Application Of Nucleic Acid Nanotechnology In The Analysis Of Chemical Luminescence

As one of the biological marcomolecules, DNA has been used to construct various nanostructures due to its physical and chemical characters. So far, DNA nanotechnology has become the most active research area in nanoscience. Nucleic acid probes constructed by DNA and RNA have the advantages of easy modification,flexible design and stability, which play an important role in design and fabricate of biosensors. In this paper, the following work has been carried out using the nucleic acid self assembly technique:First, Two DNA hairpin conformational change triggered by mi RNA target.Detection of a specific mi RNA is achieved by cascade opening of the two hairpin probes, followed by cascade polymerization and polymerization/nicking processes to continuously generate horseradish peroxidase(HRP)-mimicking DNAzymes for signal amplification.Second, we choose micro RNA-122(mi R-122), a tumor suppressor micro RNA of hepatocellular carcinoma, as a model target. Through magnetic removal of unreacted Hemin, the resultant DNA networks containing substantial HRP-mimicking DNAzymes and fluorophores FAM enable ultrasensitive CRET imaging of mi RNA-122.Third, we program an initiator triggered and catalyzed self-assembly of duplex-looped DNA hairpin motifs based on strand displacement reaction. Due to the recycling of initiator and performance in a cascade manner, this system is versatilely extended to the construction of concatenated logic circuits with a feedback function,which is further capable of operating as a biocomputing keypad-lock security system that can be automatically reset with no need of any external stimulus and human intervention. Moreover, through integrating with an isothermal amplification technique of rolling circle amplification(RCA), this programming catalyic DNA self-assembly strategy readily achieves highly sensitive biosensing of initiator.