Study On The Construction And Application Of Dual-colour Nucleic Acid Fluorescent Probe

Nucleic acid aptamer fluorescent probes were widely used in biosensors because of their high sensitivity,good selectivity and wide range of applications.However,traditional nucleic acid aptamer-based fluorescent probes usually had a single fluorescence signal,high fluorescence background and relatively high detection limits,which cannot meet the demand for quantitative determination of trace substances.In this study,three different dual-colour fluorescent probes were designed separately using a dual fluorescent group molecular beacon,a fluorescent dye-labeled aptamer of chloramphenicol and nucleic acid dye SYBR GreenⅠ,a fluorescent dye-labeled aptamer of Hg²⁺and nucleic acid dye SYBR GreenⅠ,and three rapid quantitative detection methods for different targets were developed.A highly sensitive quantitative detection for Pb²⁺in water was realized based on the fluorescent probe constructed with dual fluorescent group molecular beacon;a detection for chloramphenicol in milk was realized based on the fluorescent probe constructed with fluorescent dye-labeled chloramphenicol aptamers and nucleic acid dyes SYBR GreenⅠ;a highly sensitive quantitative detection for Hg²⁺in water was realized based on the fluorescent probe constructed with fluorescent dye-labeled aptamer of Hg²⁺and nucleic acid dye SYBR GreenⅠ.Compared with the traditional quantitative analysis method based on aptamer fluorescent probe,the analytical method developed in this paper has higher sensitivity and lower detection limit.Changing the nucleic acid aptamer in the fluorescent probe can also be used for the detection of other targets.