Nanopore Stochastic Detection of Enzymatic Reactions: Fundamentals and Practical Applications

Nanopore sensors have emerged as a label-free and amplification-free technique for measuring single molecules. First proposed in the mid 1990s, nanopore detection takes advantage of the ionic current modulations produced by the passage of target analytes through a single nanopore bathed in high salt solutions at a fixed applied potential. Over the last two decades, these nanoscale sized pores have been utilized for biosensing, sequencing DNA molecules, studying covalent and non-covalent bonding interactions, investigating biomolecular folding and unfolding, and so on. A major bottleneck of utilizing nanopore sensors for various applications is the rapid transport of target analytes through the nanopore. Many of such rapid events could not be accurately detected by the currently available recording technique. Several strategies have been used to slow down molecular and ionic transport, thus improving the resolution and sensitivity of nanopore sensors. These include variation of the experimental conditions, use of a host compound, and modification of the analyte molecule and the nanopore sensor itself. In this presentation, I will highlight some of our group’s research efforts in utilizing nanopores to investigate enzymatic reactions (in particular, protease - peptide cleavage) and exploring their various practical applications.