New Methods For The Design Of Hairpin DNA Fluorescent Probes

With the birth of the first nucleic acid synthesis and DNA chemical synthesis, markers get break through, a nucleic acid molecule probe have developed rapidly. Because the nucleic acid probe is simple in design, good stability, easy synthesis, signal mechanism flexible, by widespread application to chemistry, medicine and biology, etc. So far, many types of nucleic acid probe has developed, such as classic ucleic acid probe including RNA probe, cDNA probes and genomic DNA probe etc, the new-style nucleic acid probe including Yin Yang probe,TaqMan probe, Padlock probe, Aptamer probe, molecules beacon probe , etc.Since Tyagi and Krammer invent the molecular beacon probe in 1996, hairpin nucleic acid probe as a high selectivity and high sensitivity of new fluorescent probe been widely used. Along with the further research of hairpin nucleic acid probe and the emergence of new types hairpin nucleic acid probe, people found hairpin nucleic acid probe not only applicable in the analysis of protein and nucleic acid in vitro, also suitable for living analysis. It can also be used to analyt the interaction of drug small molecules, protein and nucleic acid, it is a powerful tool to research nucleic acid and protein interaction, also is a kind of extremely promising new nucleic acid probe. Contract with traditional nucleic acid probe, the hairpin probe can be used in detecting single base mismatch and real-time monitoring. The nucleic acid probe marker is biotin, radioactive substances and fluorescence group, etc. Among them, the fluorescent signal is less influence of biological molecules, high sensitivity and simple, become the most commonly markers. This paper focus on hairpin type of DNA fluorescence probe new method research, mainly in the following three areas:Based on room-temperature phosphorescence, designed a hairpin probe which using Eu³⁺ ion complexes as fluorescence group. Due to the Eu³⁺ ion complexes’ have a long luminescence lifetime, when used in biological samples can effectively reduce the background, improves the sensitivity.Based on mercury ion competitive ligation and fluorescence resonance energy transfer （FRET）, designed a hairpin probe which used the structure of T-Hg2+-T for stem, and it is used to detection biological sulfur with high sensitivity.Based on some heterocyclic fluorescence small molecules can inset in Abasic site, designed a label-free hairpin fluorescence nucleic acid probe, and investigated experimental conditions’ s effort, also verified the rationality.