Application Study Of Super-quenching Nucleic Acid Fluorescent Probes

Objective Traditional nucleic acid fluorescent probes used for quantitative detection usually have a high fluorescence background and low signal-to-background ratio.The detection method based on these fluorescent probes has a high detection limit,which cannot meet the needs for quantitative determination of trace targets.Based on this,this study designed a series of super-quenching nucleic acid fluorescent probes for different targets.Use these fluorescent probes to achieve high-sensitivity,low-concentration quantitative detection for different targets.Methods Three different nucleic acid fluorescent probes were constructed using double-quenching molecular beacons and nucleic acid dyes Hoechst 33258;graphene oxide and three nucleic acid aptamers of metal ion(Hg²⁺,Pb²⁺and Ag⁺)labeled by different fluorescent dyes;bimetallic organic framework material Cu/UiO-66 and fluorescent dye-labeled chloramphenicol aptamer.Three new methods for quantitative detection of different targets were developed using these different fluorescent probes.Results Highly sensitive dual-color quantitative detection for single-stranded DNA in complex samples（serum）was achieved using the constructed fluorescent probe based on double-quenching molecular beacons and nucleic acid dye Hoechst 33258.One-step simultaneous detection of Hg²⁺,Pb²⁺,and Ag⁺in soil samples was achieved using the constructed fluorescent probe based on graphene oxide and three nucleic acid aptamers of metal ion labeled by different fluorescent dyes.Highly sensitive and selective quantitative detection for chloramphenicol in fish samples was achieved using the constructed fluorescent probe based on bimetallic organic framework material Cu/UiO-66 and fluorescent dye-labeled chloramphenicol aptamers.Conclusion Three different quantitative detection methods for single-stranded DNA in complex samples（serum）,metal ions in soil samples,and chloramphenicol in fish samples were developed based on different fluorescent probes.These methods have these advantages of low fluorescence background,high sensitivity,good selectivity and low detection limit.The materials used in these quantitative detection methods are all environmentally friendly and non-toxic,and have high cell affinity,which also has potential application value in cell detection.