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Updated: Aug 10, 2026

Membrane Transport Processes Analyzed by a Highly Parallel Nanopore Chip System at Single Protein Resolution
Published on: August 16, 2016
pH-controlled diffusion of proteins with different pI values across a nanochannel on a chip
Reto B Schoch1, Arnaud Bertsch, Philippe Renaud
1Microsystems Laboratory, STI-LMIS, EPFL, CH-1015 Lausanne, Switzerland. reto.schoch@epfl.ch
Abstract:
Electrostatic interactions dominate the diffusion of proteins in a nanochannel, which was measured and modeled for pH values above and below the isoelectric points of three lectin proteins. Maximal diffusion coefficients were obtained when the proteins were neutral at their pI. This pH-controlled transport led to a separation of biomolecules across the nanochannel. A pI shift was observed, due to reversible adsorption of proteins on the walls, which affects the pH in the nanochannel.

