Papers by Keyword: Molecular Beacon

Abstract: A sensitive fluorescent biosensing strategy based on structure-switching of molecular beacon for the detection of single nucleotide polymorphism is proposed in this study. In the absence of target DNA, only low background fluorescence can be detected since the formation of hairpin structure induces close proximity of fluorophore and quencher. On the contrary, the fluorescence intensity increases significantly after introduction of target DNA because structure-switching of molecular beacon results in separation of fluorophore and quencher. The change of fluorescence intensity is linear with concentration of target DNA, and a molecular beacon-based sensing system for fluorescent detection of single nucleotide polymorphism is fabricated. The target DNA can be sensitively detected in a linear dynamic range from 17.58nM-1.125μM with a low detection limit of 8 nM. Moreover, good reproducibility and high specificity are achieved.

Abstract: Multiple-valued logic is an extended form of Boolean logic. In daily life, people often encounter the problem about the multiple-valued logic. With further study on Boolean logic, multiple-valued logic has been paid more and more attention by researchers. This paper achieves the operation of AND gate in three-valued logic by using the DNA hairpin structure. The experiment makes the DNA hairpin structure as the basic structure, and the molecular beacon as the input signal, and at last judges the logical results according to the intensity of fluorescence and gel electrophoresis. This method has the advantages that it has high sensitivity, good feasibility, and it is easy to observe. In addition, this method reduces the hybrid competition to a certain extent, and it is a new attempt to the research on multiple-valued logic.

Abstract: A new DNA computing model to realize binary integer additions based on molecular beacon is described in this paper. The binary 0 and 1 are represented by two different fluorescent states of a molecular beacon since its two different structures. By designing sequences of molecular beacons skillfully, and using the relationship between each two corresponding bits and their result and carry bit of two operational numbers, the computing process to compute each two corresponding bits of the binary numbers is simulated in the test tube. Finally, the results can be read only by detecting whether the fluorescence in tube emits. The result of the experiment shows that the algorithm is simple and convenient, and the algorithm provides a new idea for DNA computing to realize arithmetic operations

Abstract: A novel stem-loop structured fluorescent oligoDNA probe (molecular beacon probe) bearing a silylated pyrene derivative at C-5 position of deoxyuridine has been synthesized. The fluorescently labeled modified nucleoside has been incorporated into two consecutive positions in the stem segment of the DNA using an automated DNA synthesizer. The resulting modified DNA exhibited an excimer fluorescent signal upon binding to the fully matched complementary DNA strand. The excimer emission was, however, effectively quenched while it stays alone or it hybridizes to a single base mismatched complementary target.