We have integrated multiple nanopores in series into glass microfluidic devices and evaluated resistive-pulse sensing of hepatitis B virus (HBV) capsids. Nanopore sensors are well suited to study biological particles, such as virus capsids, due to the ability to resolve single particle events in solution and on short timescales, e.g., milliseconds to seconds.  In addition, small differences in analyte size, e.g., 5 nm in diameter, are easily discriminated on these devices, which can be used to study HBV self-assembly.  To fabricate the devices, V-shaped microchannels are first created in a glass substrate by UV photolithography and chemical etching. A focused ion beam (FIB) instrument is then used to pattern nanochannels in the substrate between the two microchannels. Each nanochannel has three asymmetrically spaced nanopores, and each pore is 50-nm wide, 50-nm deep, and 300-nm long. In the resistive-pulse sensing experiments, HBV capsids in HEPES buffer with 1 M NaCl are placed in the device and driven through the nanochannel with a positive potential. Single particle events are observed when a capsid enters a pore and displaces the supporting electrolyte, which, in turn, increases the resistance and lowers the observed current. Each current pulse corresponds to the passage of one capsid through one nanopore, and the pulse amplitude is proportional to the capsid size. We have analyzed mixtures of different ratios of T=3 (31-nm diameter) and T=4 (36-nm diameter) HBV capsids, and the results from these experiments will be reported.

Multipore nanofluidic devices for characterization of hepatitis B virus

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.