Research And Analysis Of Organic Small Molecule-nucleic Acid Macromolecular Interactions

The progress on novel methods in biosensor has promoted the development of analytical chemistry and life science. They play important roles in interdisciplinary field of analytical chemistry and life science. So, most analytical chemistry and biomedical researchers are committed to the study of new methods of biological sensing. Nucleic acid probes have attracted more and more attention with the advantages of easy design, flexible signal transduction and so on. Here, the purpose of this article is to develop different methods based on the nucleic acid probe.This article includes the following three parts:Part one IntroductionAt first, the basic concept of nucleic acid probe was summarized, especially the advantages of aptamer and HIV RNA. Then a variety of chemical analysis methods based on the nucleic acid probes were illustrated. Finally, the contents and significance of the research were proposed.Part two A sensitive aptasensor for colorimetric detection of adenosine triphosphate based on the protective effect of ATP-aptamer complexes on unmodified gold nanoparticlesAdenosine triphosphate (ATP) is the most direct source of energy in organisms, and the quantitative analysis of ATP is of great significance in medical research, life sciences, food safety, environmental monitoring and some other fields. This study is the first to demonstrate that ATP-aptamer complexes provide greater protection for unmodified gold nanoparticles (AuNPs) against salt-induced aggregation than either aptamer or ATP alone. This protective effect was confirmed using transmission electron microscopy, dynamic light scattering, Zeta potential measurement, and fluorescence polarization techniques. Utilizing controlled particle aggregation/dispersion as agauge, a sensitive and selective aptasensor for colorimetric detection of ATP was developed using ATP-binding aptamers as the identification element and unmodified AuNPs as the probe. This aptasensor exhibited a good linear relationship between the absorbance and the logarithm concentration of ATP within a 50-1000 nM range. ATP analogs such as guanosine triphosphate. uridine triphosphate and cvtidine triohosphate resulted in little or no interference in the determination of ATP.Part three Label-free fluorescent detection of aminoglycoside antibiotics based on the interaction of ligand-HIV RNAStudies of the interaction between small molecule ligands and functional biomacromolecules provide opportunities for the discovery of new compounds that can efficiently regulate the specific biological processes. Ribonucleic acid (RNA) molecules have become attractive drug targets since the discovery of their roles in the regulation of gene expression. However so far, only a limited number of studies have investigated interactions between ligands and functional RNA molecules, especially those based on fluorescence. And the quantitative determination of aminoglycoside antibiotics is necessary for clinical medicine and pharmaceutical analysis. The Rev-response element (RRE) RNA was found to quench the fluorescence of proflavine effectively. So the proflavine fluorescence was quenched by different concentration of RRE RNA and the mechanism was explored firstly. It was previously reported aminoglycoside antibiotics can also specifically bind to HIV-1 RRE RNA, furthermore, it was found that after adding aminoglycoside antibiotics to RRE RNA-proflavine mixtures, the fluorescence of the proflavine recovered due to interactions between aminoglycoside antibiotics with RRE RNA. Accordingly, based on the interactions between small molecules and RRE RNA, a new strategy for the detection of aminoglycoside antibiotics was developed using off-on proflavine as fluorescence probe in the study.