| Nanopore system is important for its many promising applications in rapid DNA sequencing, large biological molecule detection, polynucleotide-enzyme interaction study and etc. Following the first introduction of nanopores for polynucleotide study twelve years ago, many research studies have focused on the development of synthetic nanopore systems, due to its adjustability and adaptability for meeting various application needs, and the potential integration into future nano devices.;Given the broad potential technological importance, it's highly desirable to develop a reliable yet convenient fabrication method for nanopore system. We introduce a novel fast and low-cost technique for fabricating nanopore system with soft materials, employing a low-power laser with lithography-free substrate preparation. A model of surface-tension driven mass flow is proposed to describe its mechanism of formation. We further demonstrate the soft nanopore system's capability for sensing biological molecules with DNA characterization experiments.;A solid-state nanopore based system with optical access is introduced for the purpose of manipulating DNA-tethered microspheres near the nanopore using optical tweezers. We use optical trap to anchor lambda-DNA-tethered microspheres in close proximity (1 ∼ 3mum) to the solid-state nanopore, and study the ionic conductance through the voltage-biased nanopore. At high voltage (-100mV to -300mV), we observe hundreds of free-DNA-translocation-like current suppressions. We present the finding and discuss its possible underlying mechanism. |
