Nanopipette delivery: influence of surface charge

Shi, Wenqing; Sa, Niya; Thakar, Rahul; Baker, Lane A.

doi:10.1039/c4an01073f

Cited by 35 publications

(40 citation statements)

References 44 publications

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“…[18][19][20] These applications use the changes in ionic current through the end of the nanopipette (with an applied bias), as a single entity passes through the end of the probe, to provide diagnostic information. Furthermore, these probes constitute powerful tools for the delivery of molecules, including drugs and other stimuli, 16,21,22 to surfaces and interfaces. Nanopipettes have also been used extensively as chemical sensors, detecting, for example, pH, 9 sodium, 23 potassium 24 and other ions as well as dopamine 25 and DNA molecules.…”

Section: Introductionmentioning

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: Introductionmentioning

confidence: 99%

Characterization of Nanopipettes

et al. 2016

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“…An alternative strategy for controlling the delivery of ions made use of a nanopipette with a carbon ring surrounding its orifice [84]. The electroactive ionic species delivered from the pipette to external solution were electrochemically detected at the ring, and fluorescein was utilized to optically map ion enrichment/depletion in the nanopipette tip.…”

Section: Delivery From Nanopipettes Under Resistive-pulse or Current mentioning

confidence: 99%

Resistive-pulse and rectification sensing with glass and carbon nanopipettes

Wang

Mirkin

2017

Proc. R. Soc. A.

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Along with more prevalent solid-state nanopores, glass or quartz nanopipettes have found applications in resistive-pulse and rectification sensing. Their advantages include the ease of fabrication, small physical size and needle-like geometry, rendering them useful for local measurements in small spaces and delivery of nanoparticles/biomolecules. Carbon nanopipettes fabricated by depositing a thin carbon layer on the inner wall of a quartz pipette provide additional means for detecting electroactive species and fine-tuning the current rectification properties. In this paper, we discuss the fundamentals of resistivepulse sensing with nanopipettes and our recent studies of current rectification in carbon pipettes.

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“…The SICM nanopipette can also be used as a reservoir of analyte (e.g. DNA) that can then be delivered to a surface in a highly localized manner by controlling the bias of the QRCE in the nanopipette [16,[74][75][76][77][78]. Such studies have potential application in the delivery of particular molecules and therapeutics to a specific cell or subcellular region.…”

Section: (D) Conductance Measurements Local Delivery and Sizingmentioning

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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Nanopipette delivery: influence of surface charge

Cited by 35 publications

References 44 publications

Characterization of Nanopipettes

Characterization of Nanopipettes

Resistive-pulse and rectification sensing with glass and carbon nanopipettes

Multifunctional scanning ion conductance microscopy

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