Programmable Delivery of DNA through a Nanopipet

Ying, Liming; Bruckbauer, Andreas; Rothery, Alison M.; Korchev, Yuri E.; Klenerman, David

doi:10.1021/ac015674m

Cited by 86 publications

(102 citation statements)

References 43 publications

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“…Nanopipettes have recently been used to write high-resolution DNA and protein patterns on surfaces in the presence of a surrounding liquid and with the use of electrical fields to control the flow of reagents from the pipette tip to the surfaces. [312,313] Coaxial pipettes were also used for releasing neurotransmitters to a neuronal network with spatial control. [314] These two techniques are elegant but may lack versatility and convenience for a range of applications.…”

Section: Non-contact Microfluidics Operating Under a Liquidmentioning

confidence: 99%

Microfluidics for Processing Surfaces and Miniaturizing Biological Assays

2005

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This review is an account of our efforts to develop a versatile and flexible microfluidic technology for surface‐processing applications and miniaturizing biological assays. The review is presented in the context of current trends in microfluidic technology and addresses some of the major challenges for confining chemical and biochemical processes on surfaces: the sealing of a microchannel with a surface, the world‐to‐chip interface, the displacement of liquids in small conduits, the sequential delivery of multiple solutions, the accurate patterning of surfaces, the coincident detection of various analytes, and the detection of analytes in a small and dilute sample. Our solutions to these problems include the use of reversible sealing, capillary phenomena for powering and controlling liquid transport, and non‐contact microfluidics for spotting and drawing (on surfaces) with flow conditions. These solutions offer many advantages over conventional techniques for handling minute amounts of liquids and may find applications in lithography, biopatterning (e.g., the patterning of biomolecules), diagnostics, drug discovery, and also cellular assays.

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Section: Non-contact Microfluidics Operating Under a Liquidmentioning

confidence: 99%

Microfluidics for Processing Surfaces and Miniaturizing Biological Assays

2005

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“…We previously utilized the very high electricfield gradients generated at the tip of a nanopipette to controllably concentrate and deliver DNA. [21][22][23] The pipettes have an inner diameter of 100 nm and the voltage drop occurs in the last few microns of the tip owing to its tapered shape. By application of a potential of 1 V between the electrode in the bath and the electrode in the pipette, a very high electric field of % 8000 V cm À1 is generated at the tip of the pipette.…”

mentioning

confidence: 99%

Individual Molecules of Dye‐Labeled DNA Act as a Reversible Two‐Color Switch upon Application of an Electric Field

et al. 2004

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Over the past few years, molecular switches have been heavily researched in the quest for molecular electronic devices. Some switching systems operate by a conformational change in the molecule which is induced by either an electric field, [1,2] an STM (scanning tunneling microscope) tip, [3] an electrochemical reaction, [4] or light. [5] Alternatively, molecular switches can be operated nonconformationally by redox reactions [6] or a chemical binding event. [7] Biomolecules have recently been adapted for new purposes; for example, DNA has been used as part of a conducting wire, [8] a molecular machine, [9][10][11][12] a crystal template, [13] a scaffold for nanoscale construction, [14] and even as a component of a "computing machine". [15,16] Herein we show that the fluorescence of individual dye-labeled DNA molecules can be reversibly switched from green to red and vice versa upon application of an electric field.The use of nucleic acids as molecular switches is a relatively new concept and, so far, has had limited success. The use of an electric field to modulate the fluorescence of labeled DNA adsorbed onto an electrode [17] and the use of a magnetic field to control the hybridization state of DNA [18] are known. Conformational switching of DNA by the variation of buffer conditions, [11,19] the binding of adenosine to an aptamer sequence on DNA, [20] or the binding of singlestranded DNA (ssDNA) to a DNA quadruplex [9] have also recently been reported. The main limitation with the current mechanisms for DNA conformational switches is that they require bimolecular hybridization or a change of buffer, thus switching is slow. Furthermore, in some cases switching is not reversible [20] or the process creates undesirable "waste" DNA. [9,10] Our DNA switch overcomes these problems by using an electric field to alter the DNA-dye interaction which renders the switching process rapid (< 100 ms) and reversible with no by-products.Here a controllable electric field and single-molecule fluorescence detection were used to probe the switching of the fluorescent states of individual DNA molecules that were labeled with two different fluorophores at the same end of the DNA duplex. We previously utilized the very high electricfield gradients generated at the tip of a nanopipette to controllably concentrate and deliver DNA. [21][22][23] The pipettes have an inner diameter of 100 nm and the voltage drop occurs in the last few microns of the tip owing to its tapered shape. By application of a potential of 1 V between the electrode in the bath and the electrode in the pipette, a very high electric field of % 8000 V cm À1 is generated at the tip of the pipette.[22]The fluorescence of both fluorophores was detected simultaneously with either two-color direct excitation of both fluorophores or single-color excitation of the donor fluorophore only. In the latter experiments, the excited-state energy is transferred nonradiatively from a donor to an acceptor fluorophore by FRET (fluorescence resonance energy transfer). The efficiency of...

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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%

“…This approach has been used to study endocytic pathways [150], such as probing the mechanism of clathrin-coated pit closure [151]. Additionally fluorescence measurements have been very valuable in following the dynamics of delivery from nanopipettes and the behaviour of the fluorescent moieties while in a nanopipette [75,152]. These studies showed that it was possible to deliver a single fluorescent molecule to different subcellular regions of a boar spermatozoon and track the diffusion therein [152].…”

Section: (D) Scanning Electrochemical Microscopy-scanning Ion Conductmentioning

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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Programmable Delivery of DNA through a Nanopipet

Cited by 86 publications

References 43 publications

Microfluidics for Processing Surfaces and Miniaturizing Biological Assays

Microfluidics for Processing Surfaces and Miniaturizing Biological Assays

Individual Molecules of Dye‐Labeled DNA Act as a Reversible Two‐Color Switch upon Application of an Electric Field

Multifunctional scanning ion conductance microscopy

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