Dynamic Electrical Switching of DNA Layers on a Metal Surface

Rant, Ulrich; Arinaga, Kenji; Fujita, Shozo; Yokoyama, Naoki; Abstreiter, G.; Tornow, Marc

doi:10.1021/nl0484494

Cited by 166 publications

(212 citation statements)

References 17 publications

(26 reference statements)

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“…Under these conditions, as shown previously, the DNA is horizontally oriented towards the Au(111) surface because of electrostatic interactions of DNA with the positively charged Au (111) surface. 19,20 At the same time the, Au STM tip is negatively charged thus repelling DNA duplexes. We have observed two important features of current-distance curves recorded under these conditions as shown in figure 3B.…”

Section: Author Manuscriptmentioning

confidence: 99%

“…The 10 mM phosphate buffer + 100 mM sodium chloride solution environment in this experiment ensures that the investigated ds-DNA exists predominantly in B-form double helixes. 7,[18][19][20] Although the Au -tip distance for DNA detachment varies somewhat from experiment to experiment (s det =2.8 ± 0.6 nm), significant currents are observed for the tip-distance separation as large as 3 nm. Such large current can only be attributed to the conductivity of DNA molecules trapped in a junction indicating an enhanced electronic coupling along the ds-DNA.…”

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confidence: 99%

“…Under these experimental conditions the STM tip is charged positively (E Tip >E PZC ) and the Au(111) is charged negatively (E Au <E PZC ) with respect to the potential of the zero charge of the electrode. 19,20 It was shown previously by two independent groups that under these conditions the negatively charged DNA is repelled from the negatively charged Au(111) surface. 19,20 Thus, the DNA molecule can conceivably be stretched in the course of lifting of the STM tip.…”

mentioning

confidence: 99%

“…19,20 It was shown previously by two independent groups that under these conditions the negatively charged DNA is repelled from the negatively charged Au(111) surface. 19,20 Thus, the DNA molecule can conceivably be stretched in the course of lifting of the STM tip. As can be seen in figure 3A, similarly to experiments shown in figure 2, a wide distribution of currents ranging from about 20 pA to 950 pA is observed.…”

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confidence: 99%

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In Situ Electrochemical Distance Tunneling Spectroscopy of ds-DNA Molecules

Wierzbiński

Arndt²,

Hammond³

et al. 2006

Langmuir

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The electrical conductance of ds-DNA duplexes containing 8 to 14 base pairs modified at both ends with a -(CH 2 ) 6 -SH linker was measured in a buffered aqueous solution using electrochemically controlled distance tunneling spectroscopy. The tunneling experiment with selfcomplementary 5′-(GC) n -3′-(CH 2 ) 6 -SH (n=4-7) duplexes attached covalently to a gold STM tip and a Au(111) electrode shows a wide distribution of currents independent of the ds-DNA length. The voltage-induced horizontal orientation of ds-DNA within the junction results in decreased electrical conductance. The lower currents are also observed for ds-DNA molecules containing a single CA base mismatch. TOC imageKeywords DNA conductivity; scanning tunneling distance spectroscopy; electrochemical STM The nature of electrical transport along the DNA duplex is important in understanding DNA damage in vivo and in exploring the possible use of DNA in molecular electronics and direct detection of DNA hybridization. The ongoing scientific debate places DNA molecules in all possible electrical conductivity ranges -from an insulator to a proximity induced superconductor. [1][2][3][4] It is apparent that the experimental conditions, including the nature of the contact between the electrode and the molecule, as well as the orientation and the structure In particular, the DNA structure and flexibility depend significantly on the counter-ion and on the electrostatic interactions between the electrical contact and the molecule. 12 Thus, it is important to measure the electrical properties of single DNA molecules while rigorously controlling the electrochemical parameters of the experiment.We report here the electrochemical tunneling distance spectroscopy measurements of electrical conductance of series of ds-DNA molecules modified with a -C 6 -SH linker attached to 3′ ends of DNA in 10 mM phosphate buffer + 100 mM sodium chloride solution. This approach allows us to control the orientation of ds-DNA molecule within the STM junction by means of electrostatic interactions between the molecule and the electrochemically polarized metal contact.In a tunneling distance spectroscopy with electrochemical gate, shown schematically in figure 1A, the STM tip is first brought into close proximity of the Au(111) electrode at the initial set-point current, i 0 . The STM tip is then lifted while the x-y position is kept constant and the current-distance (i-s) curve is recorded. This experimental procedure follows the method previously used by Haiss et al. 13 to measure electrical conductivity of α,ω-alkanedithiol molecules bridging the STM gap. A similar method of measuring of molecule conductance, starting with the formation of a mechanical contact between the STM tip and a substrate, was previously introduced by Tao et al. 14 Figure 1B shows a typical current-distance (i-s) transient recorded in the absence of preadsorbed molecules on the Au(111) surface. The initial position of STM tip versus Au(111) surface is established by using a set-point current, i 0 =4nA,...

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Section: Author Manuscriptmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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confidence: 99%

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In Situ Electrochemical Distance Tunneling Spectroscopy of ds-DNA Molecules

Wierzbiński

Arndt²,

Hammond³

et al. 2006

Langmuir

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“…8 The characteristic behavior of the DNA switching, such as the switching amplitude (the difference between upright and horizontal orientations) or switching dynamics are influenced by buffer pH, ionic strength, and temperature. 9,10 Additionally, the switching amplitude is influenced by conformation changes of the immobilized DNA, making it possible to detect DNA hybridization or denaturation 11 or to utilize the platform for high-throughput characterization of the DNA sequence dependence on conformation changes that are induced by DNA binding proteins such as transcription factors. 12 We present a molecular motor, which consists of short double stranded DNA (dsDNA) probes anchored on a smart polymer surface.…”

Section: * S Supporting Informationmentioning

confidence: 99%

Precisely Controlled Smart Polymer Scaffold for Nanoscale Manipulation of Biomolecules

Spuhler¹,

Solá

Zhang³

et al. 2012

Anal. Chem.

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ABSTRACT:We demonstrate the application of a novel smart surface to modulate the orientation of immobilized double stranded DNA (dsDNA) and the conformation of a polymer scaffold through variation in buffer pH and ionic strength. An amphoteric poly(dimethylacrylamide) based coating containing weak acrylamido acids and bases, which are copolymerized together with the neutral monomer, is covalently bound to the surface. The coating can be made to contain any desired amount of buffering and titrant ionogenic monomers, allowing control of the surface charge when the surface is bathed in a given buffer pH. Spectral self-interference fluorescence microscopy (SSFM) is utilized to precisely quantify both the DNA orientation and the polymer conformation with subnanometer resolution. It is possible to utilize the polymer scaffold to functionalize a variety of common materials used in microfabrication, making it a general purpose building block for the next generation of nanomachines and biosensors.

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Stimuli‐Responsive Surfaces in Biomedical Applications

Pranzetti¹,

Preece²,

Mendes³

2013

Intelligent Stimuli‐Responsive Materials

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Nature provides mechanisms that are able to dynamically control specific and nonspecific interactions between cells and biological surfaces [1,2]. Scientists have long tried to reproduce these dynamic biological events and have recently made an important step in that direction by creating artificial stimuli-responsive surfaces [3][4][5][6][7]. These smart substrates present modulatory surface properties that are able to respond to external chemical/biochemical [8][9][10][11][12], thermal [13][14][15], electrical [16][17][18][19][20], and optical stimuli [21][22][23][24][25][26][27][28][29][30][31]. Due to their dynamic nature such substrates are very appealing for applications in the biomedical field [32]. Progress to date has led to control over biomolecule activity [33] and immobilization of a diverse array of proteins, including enzymes [34] and antibodies [35]. These prior achievements have encouraged researchers to take the challenge of using dynamic surfaces to modulate larger and more complex systems, such as bacteria [36] and mammalian cells [37].Achieving control over surface properties could provide new insights in the understanding of cell behavior and can offer distinct benefits with regard to the development of medical devices. For instance, the modulation of cell attachment and detachment could lead to the prevention of unwanted bacteria fouling on implants, reducing the risk of infections and rejection [38][39][40][41][42]. Furthermore, dynamic surfaces able to present on demand regulatory signals to a cell could provide unprecedented opportunities in studies of cell responses in real-time. Cells in tissues adhere to and interact with their extracellular environment via specialized cell-cell and cell-extracellular

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Dynamic Electrical Switching of DNA Layers on a Metal Surface

Cited by 166 publications

References 17 publications

In Situ Electrochemical Distance Tunneling Spectroscopy of ds-DNA Molecules

In Situ Electrochemical Distance Tunneling Spectroscopy of ds-DNA Molecules

Precisely Controlled Smart Polymer Scaffold for Nanoscale Manipulation of Biomolecules

Stimuli‐Responsive Surfaces in Biomedical Applications

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