High ordered Al2O3 nanochannel array has been fabricated in our lab through electrochemical etching. The size and distance between each channel can be precisely controled (ACS Nano 2008, 2(5): 959-965). Diffusion of electrically neutral molecules in such solid nanochannel has been observed (Angewandte Chemie International Edition 2010, 49: 7943-7947). By immobilizing Morpholino in nanochannels we also have detected DNA molecules in nanochannel array (ACS Nano 2010, 4(11): 6417-6424; Figure 1).
Now, we can easily etch nanochannels with funnel and branch structures and modificate the nanochannels with differnet hydrophilic/hydrophobic properties (Advanced Functional Materials, 2013, 23, 3836-3844; Figure 2), which enable us to build more bioanalizing devices.
Figure 1. SEM image of nanochannel array and the principle of DNA analysis through nanochannels