The Sensitive Detection Of Protein Through Solid-state Nanopore Modified With Tethered Lipid Layer

Proteins are known as the building blocks of life,and features prominently on bioscience.More than 500,000 different proteins are encoding by the human genome,consists of 20,000 to 30,000 genes.The traditional techniques used for proteins detection such as Ultraviolet Absorption Spectrum and Scanning Electron Microscopy are complicated,need high skilled people and high-tech equipment.To overcome these disadvantages,nanopore technology,inspired by the Coulter principle[1],may replace the other techniques used for detecting proteins.The first nanopore was a biological nanopore formed by biomolecules,and with the development and the progress of the micro-nanofabrication technologies,solid-state nanopore were fabricated on insulated films or two-dimensional materials.Solid-state nanopore is a promising technique compared to biological nanopore for proteins detection due to its significant advantages in term of controllability and stability.However,the complex surface properties of solid-state nanopores limit their application.Based on the prevailing status and problems of solid-state nanopores in protein detection,this paper is devoted to study the modification of solid-state nanopores and the application of the modified nanopores in proteins detection.Firstly,a low cost and simple solid-state nanopore fabrication technology based on dielectric breakdown is proposed.In this paper we explored a set of nanopore fabrication system on the basis of dielectric breakdown model and LabVIEW programming to fabricate a stable solid-state nanopores.And the obtained solid-state nanopore is used to detect the RecA protein and RecA-DNA complex which is important in rapid microbial identification.We proposed that the detection efficiency and the binding efficiency are relative to the binding sites otherwise,irreversible plugging was found during the experiment due to the interaction between the protein and the nanopore wall.Secondly,a bottom-up nanopore modification method was developed to tether the lipid molecule(DOPE)to the surface of SiNx nanopore by covalent bonding based on epoxy-amine reaction.Chemical,physical and electrical characterizations showed that the modified nanopore have strong stability and tolerance,and the detection of RecA protein is greatly improved.Finally,Bovine Serum Albumin(BSA)was detected by the modified nanopore.After studying the interaction between the tethered layer and BSA,we found that the adsorption is tiny under neutral pH condition.Further we showed that the modified nanopore have an excellent performance in protein detection.