title: High Temperature Extends the Range of Size Discrimination of Nonionic Polymers by a Biological Nanopore.
abstract: We explore the effect of temperature on the interaction of polydisperse mixtures of nonionic poly(ethylene glycol) (PEG) polymers of different average molar masses with the biological nanopore α-hemolysin. In contrast with what has been previously observed with various nanopores and analytes, we find that, for PEGs larger than a threshold molar mass (2000 g/mol, PEG 2000), increasing temperature increases the duration of the PEG/nanopore interaction. In the case of PEG 3400 the duration increases by up to a factor of 100 when the temperature increases from 5 °C to 45 °C. Importantly, we find that increasing temperature extends the polymer size range of application of nanopore-based single-molecule mass spectrometry (Np-SMMS)-type size discrimination. Indeed, in the case of PEG 3400, discrimination of individual molecular species of different monomer number is impossible at room temperature but is achieved when the temperature is raised to 45 °C. We interpret our observations as the consequence of a decrease of PEG solubility and a collapse of PEG molecules with higher temperatures. In addition to expanding the range of application of Np-SMMS to larger nonionic polymers, our findings highlight the crucial role of the polymer solubility for the nanopore detection.
authors.affiliation: LAMBE UMR 8587 CNRS, Cergy and Évry Universities, France.|LPTM UMR 8089 CNRS, Cergy University, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Piguet
authors.affiliation: LAMBE UMR 8587 CNRS, Cergy and Évry Universities, France.
authors.forename: Hadjer
authors.initials: H
authors.lastname: Ouldali
authors.affiliation: LAMBE UMR 8587 CNRS, Cergy and Évry Universities, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Discala
authors.affiliation: LAMBE UMR 8587 CNRS, Cergy and Évry Universities, France.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Breton
authors.affiliation: Laboratory for Membrane Physiology and Technology, Faculty of Medicine, Department of Physiology, University of Freiburg, Germany.|Freiburg Materials Research Centre, University of Freiburg, Germany.|Centre for Interactive Materials and Bioinspired Technologies, University of Freiburg, Germany.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Behrends
authors.affiliation: LAMBE UMR 8587 CNRS, Cergy and Évry Universities, France.
authors.forename: Juan
authors.initials: J
authors.lastname: Pelta
authors.affiliation: LAMBE UMR 8587 CNRS, Cergy and Évry Universities, France.
authors.forename: Abdelghani
authors.initials: A
authors.lastname: Oukhaled