Fabrication of solid-state nanopores and nanopore arrays
We use a high intensity electron beam of a field-emission Transmission Electron Microscope (TEM) for the fabrication of uniform nanopores and nanopore arrays in SiN membranes. These nanopores are used for single-molecule DNA analysis. Nanopores in the size range of 1.5 - 20 nm can be fabricated (see Figure 1). Our nanopores exhibit a truncated double-cone structure, as revealed by 3D TEM tomography measurements (see Figure 2). I-V characteristics of the nanopore are highly symmetric and scale with pore size, when taking into account the truncated double-cone structure of the pores.
Nanopore arrays are fabricated using a Scanning TEM, with a typical size distribution smaller than 0.5 nm (STD) as shown in Figure 3. This process is substantially faster compared with other state of the art techniques. Our nanopores can be assembled in micro-fluidic cells for low noise electrical current measurements. Double stranded and single stranded DNA translocations can be readily probed in the range 50 bp -50,000 bp.
- Kim, M.-J., M. Wanunu, C.D. Bell and A. Meller. (2006) Rapid Fabrication of Uniform Size Nanopores and Nanopore Arrays for Parallel DNA Analysis. Adv. Mater. 18, 3149-53
- Kim, M.-J., McNally, B., Murata, K. & Meller, A. (2007) Characteristics of solid-state nanometre pores fabricated using a transmission electron microscope. Nanotechnology. 18, 205302.
- Bell, C. D., M.-J. Kim, M. Wanunu and A. Meller (2006) Nanoscale engineering with TEM for DNA sequencing. Microsc. Microanal. 12.
Figure 1. High resolution TEM images of nanopores fabricated in 20 nm thick SiN membranes.
Figure 2. TEM tomography of a 7 nm pore, fabricated in a 50 nm SiN membrane.