Investigation Of Translocation Of Cyclodextrin And The Interaction Between Aptamer And Kanamycin By Current Pulses Through Single Bio-Nanopore Interface

As an emerging technique,nanopore single molecule detection technology has attracted extensive interest from domestic and foreign scholars because of its high sensitivity,low consumption and no need for labeling.At present,this technology is mainly used in the field of DNA sequencing,and has also made great achievements in the field of single molecule analysis.In the future,nanopore detection technology will show greater development prospects in the field of bioinformatics recognition and medical detection.The first chapter introduces the basic principle and development process of nanopore single molecule detection technology,the classification and preparation of nanopores,the formation method of phospholipid bilayer,and briefly describes the application of single molecule nanopore detection technology in different fields.Finally,we summarized the research content and research significance of this paper.In the second chapter,based on the α-HL(variant)nanopore interface,the effects of electrolyte species on β-cyclodextrin translocation and its assembly behavior with α-HL were investigated.When 1 mol/L KCl and 10 mmol/L Tris were used as electrolyte support solutions,although they were successfully assembled,there was obvious background signals at the assembly interface.However,when 1 mol/L NaCl and 10 mmol/L NaH2PO4 were used as electrolyte support solutions,the background noise at the combined interface was small and the duration was long.This combination interface can be used for the identification of chiral drugs.In the third chapter,the interaction between kanamycin and aptamer was investigated based on a single α-hemolysin(α-HL)nanopore sensing interface.The interaction selectivity over other 3 antibiotics(tetracycline,streptomycin,and gentamicin)was also investigated.It was confirmed that the GG base in the hairpin loop region of the aptamer is indeed crucial for the interaction.Based on the analysis of the aptamer translocation,it is proposed that both the length of the tail chain and the base of the loop can affect the unzipping process of hairpin DNA.This sensing interface provides a new route for exploring the specific interaction between a drug and its DNA aptamer.In conclusion,background interference caused by cyclodextrin translocation was improved based on a single α-HL nanopore interface.Meanwhile,the interaction between the aptamer and kanamycin was investigated.