Preparation Of Polyaniline Nanopore And Its Application In Single-Molecule Detection Technology

The nanopore single-molecule detection technology with advantages of simple operation,low cost,no labeling,high sensitivity,fast analysis,which has been widely used in protein conformation analysis,enzyme kinetics and metal ions analysis.Nanopore single-molecule technology also has huge potential in rapid gene sequencing.The most widely studied nanopore devices are bio-nanopores and solid-state nanopores.Compared with biological nanopores,solid-state nanopore sequencing technology has become a popular research area with its advantages of good stability,easy integration and size controllability.Nowadays,with the rapid development of new material,the practical research and application of nanopore sequencing chips with high-speed,high-throughput become possible.However,as an emerging sequencing technology,solid-state nanopores also have many challenges in manufacture,precision and so on.It is necessary strive to obtain a nanopore single molecule sequencing method with low cost,better stability,simpler operation and more practicality.Based on those problem,this study designed and synthesized polyaniline nanopore with positively charged groups.And we realized the sensing of DNA at the single molecule level with polyaniline nanopore.In view of the challenges faced by solid-state nanopore sensors,this paper mainly studies the following two aspects:Firstly,we studied the manufacture process of polyaniline nanotubes,prepared polyaniline nanotubes on polycarbonate membrane(PC membrane)by template method,and inserted polyaniline nanotubes into phospholipid membrane with the aid of liposomes for the first time.Thus,polyaniline nanochannel single-molecule sensor was constructed.It was verified that the electrostatic adsorption of DNA by polyaniline nanochannel can slow down the translocation rate of DNA.And we distinguished the translocation signals of DNA homopolymers: poly(d A),poly(d T)and poly(d C)at single molecule level.Secondly,in view of the poor stability of phospholipid membrane,the preparation and application of polyaniline nanopore was further studied.For the first time,asymmetric polyaniline nanopore were prepared on track-etched PC film.And we explored its application in DNA detection.Based on the statistics of the amplitude and dwell time of DNA translocation signal,we analyzed translocation behavior of DNA through polyaniline nanopore under different conditions.And results reveal that polyaniline nanopore can distinguish ssDNA and ds DNA signals based on blockage amplitude and translocation time.