Nanopore Sensing For The Translocation Of Nanoparticles Assembled By DNA Hybridization

In rencent years,as one of the third generation of DNA sequencing,the nanopore sensors have been developed into a mature single molecule detection technology.Nanopores have been widely used for miRNA detection,discrimination between nucleic acid classes,detection of DNA binding,measurements of molecular forces,and nanoparticle detection.Gold nanoparticles(AuNPs)are a type of widely used nanomaterials with unique chemical and physical properties.Self-assembled metal nanostructures have attracted widespread attention as a result of great progress.In this paper,combined nanopore sensing with AuNPs-assembly technology,the translocation characteristic and mechanism of AuNPs and assembly have been investigated.The works provide guidance for the detection of cancer biomarkers and nano-materials in the future.The main contents are as follows:1.The ionic current blockage caused by AuNPs translocation through voltage-biased silicon nitride nanopores in ionic solution has been studied.By analyzing time duration and the integral of current blockage,nanoparticle's size,concentration and dynamics of the particle's translocation behavior can be screened.At the same time,it is shown that the direction of blocked current is connected with the diameter of nanopore.The nanopores with diameter of 40,78 and 120 nm were used to detect the AuNPs.According to theoretical analysis,the results show that translocation events increase the nanopore current and in others,events decrease the current,for smaller and larger diameter nanopores,respectively.2.MiRNAs detection based on the nanopore sensor and nanoparticle self-assembly.MiRNAs are short noncoding RNA molecules which are important in regulating gene expression.In this work,a novel miRNA detection assay has been developed,which integrates two complementary nanotechnology systems,namely,a highly selective nanoparticle self-assembly and a single-particle sensitive nanopore readout platform.Herein the barcode probe approach can also be used for multiple miRNA detection.The detection system brokes though the limitation of nanopore's size and improves the nanopore detection system.The unique combination of nanoparticle assemble and nanopore sensing presented in this work brings forth a rapid,specific,label-free biosensing strategy that can potentially be developed for point-of-care application.3.Nanopore sensing nanochain designed by DNA orgami.For the high throughput and multivariate selectivity,a type of topological variable nanoribbon has been designed as the DNA carrier by DNA origami technology.As a transport template,the nanoribbon is used to assembleAuNPs to form a linear gold nano-chain.Next,the long nano-chains have been translocated through nanopores and give rise to a series of unique ionic current blockades which contains the location and number information of AuNPs bounded on the nano-chain.The creation of a new type of nanopore sensor provides a new way of thinking.