Siddharth Shekar, David J. Niedzwiecki, Chen-Chi Chien, Peijie Ong, Daniel A. Fleischer, Jianxun Lin, Jacob K. Rosenstein, Marija Drndić, Kenneth L. Shepard. Measurement of DNA Translocation Dynamics in a Solid-State Nanopore at 100 ns Temporal Resolution NanoLetters DOI: 10.1021/acs.nanolett.6b01661
Despite the potential for nanopores to be a platform for high-bandwidth study of single-molecule systems, ionic current measurements through nanopores have been limited in their temporal resolution by noise arising from poorly optimized measurement electronics and large parasitic capacitances in the nanopore membranes. Here, we present a complementary metal-oxide-semiconductor (CMOS) nanopore (CNP) amplifier capable of low noise recordings at an unprecedented 10 MHz bandwidth. When integrated with state-of-the-art solid-state nanopores in silicon nitride membranes, we achieve an SNR of greater than 10 for ssDNA translocations at a measurement bandwidth of 5 MHz, which represents the fastest ion current recordings through nanopores reported to date. We observe transient features in ssDNA translocation events that are as short as 200 ns, which are hidden even at bandwidths as high as 1 MHz. These features offer further insights into the translocation kinetics of molecules entering and exiting the pore. This platform highlights the advantages of high-bandwidth translocation measurements made possible by integrating nanopores and custom-designed electronics.