Dynamic assembly of surface structures in living cells

Gorelik, Julia; Shevchuk, Andrew; Frolenkov, Gregory I.; Diakonov, Ivan; Lab, Max J.; Kros, Corné J.; Richardson, Guy P.; Vodyanoy, Igor; Edwards, C. R. W.; Klenerman, David; Korchev, Yuri E.

doi:10.1073/pnas.1030502100

Cited by 167 publications

(169 citation statements)

References 28 publications

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“…Typical SICM experiments are performed in moderate 19 to high ionic strengths (>100 mM), 3,31,32,45,67,68 as are many nanopipette measurements. 14,15,18,19 Under these conditions, the diffuse double layer is expected to be compressed to a sub-nanometer scale, and therefore undetectable, level according to: 50…”

Section: Characterization Of Nanopipettes In High Ionic Strength Mediamentioning

confidence: 99%

Characterization of Nanopipettes

et al. 2016

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Nanopipettes are widely used in electrochemical and analytical techniques as tools for sizing, sequencing, sensing, delivery and imaging. For all of these applications, the response of a nanopipette is strongly affected by its geometry and surface chemistry. As the size of nanopipettes becomes smaller, precise geometric characterization is increasingly important, especially if nanopipette probes are to be used for quantitative studies and analysis. This contribution highlights the combination of data from voltage-scanning ion conductivity experiments, transmission electron microscopy (TEM) and finite element method (FEM) simulations to fully characterize nanopipette geometry and surface charge characteristics, with an accuracy not achievable using existing approaches. Indeed, it is shown that presently used methods for nanopipette characterization can lead to highly erroneous information on nanopipettes. The new approach to characterization further facilitates high-level quantification of the behavior of nanopipettes in electrochemical systems, as demonstrated herein for a scanning ion conductance microscope (SICM) setup.

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Section: Characterization Of Nanopipettes In High Ionic Strength Mediamentioning

confidence: 99%

Characterization of Nanopipettes

et al. 2016

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“…As the nanopipette-surface distance decreases, the solution resistance in the probe-surface gap increases which, in turn, reduces the ion current. This decrease in ion current is used as a non-contact signal to sense the nanopipette-surface distance and ultimately for topographical imaging, [14][15][16] proving particularly effective for soft samples. 10,12 SICM is typically operated in aqueous solutions with relatively high ionic strength.…”

Section: Introductionmentioning

confidence: 99%

Surface Charge Mapping with a Nanopipette

et al. 2014

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Nanopipettes are emerging as simple but powerful tools for probing chemistry at the nanoscale.In this contribution the use of nanopipettes for simultaneous surface charge mapping and topographical imaging is demonstrated, using a scanning ion conductance microscopy (SICM) format. When a nanopipette is positioned close to a surface in electrolyte solution the direct ion current (DC), driven by an applied bias between a quasi-reference counter electrode (QRCE) in the nanopipette and a second QRCE in the bulk solution is sensitive to surface charge. The charge sensitivity arises because the diffuse double layers at the nanopipette and the surface interact, creating a perm-selective region which becomes increasingly significant at low ionic strengths (10 mM 1:1 aqueous electrolyte herein). This leads to a polarity-dependent ion current and surface-induced rectification as the bias is varied. Using distance-modulated SICM, which induces an alternating ion current component (AC) by periodically modulating the distance between the nanopipette and the surface, the effect of surface charge on the DC and AC is explored and rationalized. The impact of surface charge on the AC phase (with respect to the driving sinusoidal signal) is highlighted in particular; this quantity shows a shift that is highly sensitive to interfacial charge and provides the basis for visualizing charge simultaneously with topography. The studies herein highlight the use of nanopipettes for functional imaging with applications from cell biology to materials characterization where understanding surface charge is of key importance.3

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“…Some studies have considered the fluctuation of the cell volume as a function of time via the acquisition of multiple topographical maps [48,61,62], while others improved the scan rate (image time) to study the dynamics of subcellular structures [50] such as microvilli [63] or processes including exocytosis [64] and the cell cycle [3]. Phenotypic changes in cell morphology [65,66] have also been used as a diagnostic tool for a variety of conditions including heart disorders [67] and Alzheimer's disease [68].…”

Section: (C) Topographical Imaging Of Living Cellsmentioning

confidence: 99%

Multifunctional scanning ion conductance microscopy

2017

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Scanning ion conductance microscopy (SICM) is a nanopipette-based technique that has traditionally been used to image topography or to deliver species to an interface, particularly in a biological setting. This article highlights the recent blossoming of SICM into a technique with a much greater diversity of applications and capability that can be used either standalone, with advanced control (potential-time) functions, or in tandem with other methods. SICM can be used to elucidate functional information about interfaces, such as surface charge density or electrochemical activity (ion fluxes). Using a multi-barrel probe format, SICM-related techniques can be employed to deposit nanoscale three-dimensional structures and further functionality is realized when SICM is combined with scanning electrochemical microscopy (SECM), with simultaneous measurements from a single probe opening up considerable prospects for multifunctional imaging. SICM studies are greatly enhanced by finite-element method modelling for quantitative treatment of issues such as resolution, surface charge and (tip) geometry effects. SICM is particularly applicable to the study of living systems, notably single cells, although applications extend to materials characterization and to new methods of printing and nanofabrication. A more thorough understanding of the electrochemical principles and properties of SICM provides a foundation for significant applications of SICM in electrochemistry and interfacial science.

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Dynamic assembly of surface structures in living cells

Cited by 167 publications

References 28 publications

Characterization of Nanopipettes

Characterization of Nanopipettes

Surface Charge Mapping with a Nanopipette

Multifunctional scanning ion conductance microscopy

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