Wednesday, November 7, 2007 - 1:20 PM
434c

New Platform For Detecting DNA Translocation

Zhu Chen1, David P. Adams2, Michael Joseph Vasile2, Carter Hodges2, Ying-Bing Jiang2, Nanguo Liu3, and C Jeffery Brinker2. (1) Chemical & Nuclear Engineering, University of New Mexico, Advanced Material Laboratory, 1001 University Blvd. NE, Suite 100, Albuquerque, NM 87106, (2) Sandia National Laboratory, (3) Los Alamos National Laboratory, NM

Research in translocation of biopolymers like DNA and RNA through membrane channels is of great current interests in biology and biophysics. Up to now, there are mainly two approaches: one is using biological nanopores like ?-hemolysin and the other is using solid-state nanopores fabricated by top-down processes like focused-ion-beam lithography (FIB). This talk will present a new approach combining Evaporation-Induced Self-Assembly (EISA) of ordered nanoporous films with FIB. FIB is used to drill a sub-100-nm hole in a thin silicon nitride membrane. EISA is used to deposit a free-standing array of several nm diameter pores spanning the FIBed hole. This platform overcomes the problem of mesoporous thin film having too many repeating copies of mesopores by limiting the number of mesopores in a FIB-defined area, while at the same time utilizes the advantages of mesoporous thin film by EISA for the well controlled pore size, pore structure and surface chemistry, which is important for fundamental research toward DNA characteristics and DNA/pore wall interactions during translocation. DNA translocation experiments not only show that current blockage events can be detected by this new platform, but also demonstrate some interesting properties over the solid-state nanopore approach such as longer translocation times which might be important for DNA analysis. The influence of different factors such as surface properties of nanopore/nanochannel on DNA translocation will also be discussed in this talk.