Research On Quantitative And Qualitative Of Biomolecules Based On Nanopore

Nanopore single-molecule technology was emerging in the 1990 s.Nanopore single-molecule technology with effectively and low-cost has been provided a powerful platform for the widely application in biology and chemistry.Nowadays,nanopore sequencing in DNA has acquired remarkable achievements.Currently,nanopore-based systems are employed for sensing a variety of analytes,including metal ions,small molecules,DNA,RNA,proteins,and enzymes.Here,we will elaborate from the following two aspects:1?Multiple Protein Biomarkers were unambiguous Discrimination by nanoporeThe onset and progression of many diseases are often closely associated with the changes in expression of multiple biomarkers.Therefore,correct disease diagnosis usually requires multiplex detection of several molecules,which can not only improve diagnostic precision but also provide guidance for individualized,targeted therapy.The detection strategy was based on aptamer recognition and DNA-based nanopore sensing.The probes were formed by hybridization of three DNA sequences(Schematic 1),including capture arm,cDNA,and target-specific aptamer which was immobilized on magnetic beads.The presence of the target protein caused unwinding of the aptamer-capture DNA structure,releasing the capture arm-cDNA hybrid(designated here as output DNA),the single-stranded domain of which served as a guide leading the complex into the nanocavity of the nanopore.The interaction of the hybrid with the pore generated characteristic current events whose frequency could be recorded and used to quantify proteins.This system enabled discrimination among multiple protein biomarkers and their simultaneous highly accurate detection in complex mixtures using a single nanopore.2?Aerolysin nanopore was used to distinguish twenty amino acidAmino acids are organic compounds containing basic amino groups and acidic carboxyl groups.In addition,amino acids were primary substance for nutrient protein,which played the importance roles human metabolism.Therefore,it is an importance signification that accurately and precisely distinguishing the different amino acids in the proteins sequencing.Moreover,the nanopore sequencing contributed to early diagnosis and treatment for much intractable diseases.Efforts to sequence single protein molecules in nanopores have been hampered by the lack of techniques with sufficient sensitivity to discern the subtle molecular differences among all twenty amino acids.Here we report ionic current detection of all twenty proteinogenic amino acids in an aerolysin nanopore with the help of a short polycationic carrier.We chemically linked single amino acids to a short polycationic carrier–arginine heptapeptide to enable capture by the nanopore,because heptapeptides have been shown to produce well defined ionic current blockades in an aerolysin nanopore.