Nanofluidic Devices with Two Pores in Series for Resistive-Pulse Sensing of Single Virus Capsids

Abstract

We report fabrication and characterization of nanochannel devices with two nanopores in series for resistive-pulse sensing of hepatitis B virus (HBV) capsids. The nanochannel and two pores are patterned by electron beam lithography between two microchannels and etched by reactive ion etching. The two nanopores are 50-nm wide, 50-nm deep, and 40-nm long and are spaced 2.0-μm apart. The nanochannel that brackets the two pores is 20x wider (1 μm) to reduce the electrical resistance adjacent to the two pores and to ensure the current returns to its baseline value between resistive-pulse events. Average pulse amplitudes differ by <2% between the two pores and demonstrate the fabrication technique is able to produce pores with nearly identical geometries. Because the two nanopores in series sense single particles at two discrete locations, particle properties, e.g., electrophoretic mobility, are determined from the pore-to-pore transit time.

Pores with Longitudinal Irregularities Distinguish Objects by Shape

“…3 The resistive-pulse technique has been widely applied to size single molecules, viruses, particles and cells. [1][2][3][4][5][6][7][8][9][10][11][12] A single object passing through a pore causes a transient change of the system resistance, which is detected as a transient change of the transmembrane current, called a resistive-pulse. 6,7 The pulse amplitude is a measure of the object size while the pulse duration can be correlated with its surface charge.…”

Stiff filamentous virus translocations through solid-state nanopores

“…The possibility of applying nanopores to the analysis of nucleic acids, in particular DNA sequencing, has generated interest 3 , and motivated fundamental studies of the physics of nanopore translocations [4][5][6][7][8][9][10][11][12][13][14][15][16][17] . The uses of solid-state nanopores have recently expanded to include detecting single proteins 18 , mapping structural features along RecA-bound DNA-protein complexes 19 and detecting spherical and icosahedral virus strains [20][21][22] . Such advances underline the importance of expanding our understanding of nanopore translocations beyond the case of DNA.…”

Ion track symmetric and asymmetric nanopores in polyethylene terephthalate foils for versatile applications

“…In case the pore ends are oppositely charged a geometrically symmetric membrane with ionic rectification property can be fabricated [28]. Another potential application of the pores with two narrow ends is the combination of resistive pulse sensing with electrophoretic time-of-flight measurements [29,30].…”