title: Pores with longitudinal irregularities distinguish objects by shape.
abstract: The resistive-pulse technique has been used to detect and size objects which pass through a single pore. The amplitude of the ion current change observed when a particle is in the pore is correlated with the particle volume. Up to date, however, the resistive-pulse approach has not been able to distinguish between objects of similar volume but different shapes. In this manuscript, we propose using pores with longitudinal irregularities as a sensitive tool capable of distinguishing spherical and rod-shaped particles with different lengths. The ion current modulations within resulting resistive pulses carry information on the length of passing objects. The performed experiments also indicate the rods rotate while translocating, and displace an effective volume that is larger than their geometrical volume, and which also depends on the pore diameter.
authors: †Department of Physics and Astronomy, University of California, Irvine, California 92697, United States.|‡School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, China.
authors: Yinghua
authors: Y
authors: Qiu
authors: †Department of Physics and Astronomy, University of California, Irvine, California 92697, United States.
authors: Preston
authors: P
authors: Hinkle
authors: §Department of Chemistry, University of California, Irvine, California 92697, United States.
authors: Crystal
authors: C
authors: Yang
authors: ∥Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands.
authors: Henriette E
authors: HE
authors: Bakker
authors: †Department of Physics and Astronomy, University of California, Irvine, California 92697, United States.
authors: Matthew
authors: M
authors: Schiel
authors: ⊥Department of Physics, Nankai University, Tianjin 300457, China.
authors: Hong
authors: H
authors: Wang
authors: #Department of Physics, Clarkson University, Potsdam New York 13699, United States.
authors: Dmitriy
authors: D
authors: Melnikov
authors: #Department of Physics, Clarkson University, Potsdam New York 13699, United States.
authors: Maria
authors: M
authors: Gracheva
authors: ∇Department of Materials Science, GSI Helmholtz Center for Heavy Ion Research, Darmstadt 64291, Germany.
authors: Maria Eugenia
authors: ME
authors: Toimil-Molares
authors: ∥Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands.
authors: Arnout
authors: A
authors: Imhof
authors: †Department of Physics and Astronomy, University of California, Irvine, California 92697, United States.|§Department of Chemistry, University of California, Irvine, California 92697, United States.|⊗Department of Biomedical Engineering, University of California, Irvine, California 92697, United States.
authors: Zuzanna S
authors: ZS
authors: Siwy
keywords: electroosmosis; excluded volume; pore; resistive-pulse; rod; rotation