Scanning Probe Microscopy

Louder, D.; Parkinson, B. A.

doi:10.1021/ac00084a005

Cited by 26 publications

(8 citation statements)

References 325 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since its recent introduction, atomic force microscopy (AFM) has been extensively used for imaging biological molecules. − The AFM technique allows the examination of biological specimens without the need for chemical fixation/dehydration or growth of crystals, which is normally associated with other high-resolution techniques. ,, In fact, samples may be imaged with AFM under liquids at physiological concentrations and pH . A number of groups have utilized the high resolution (∼1 Å) of the AFM for examination of 2D crystallization of protein molecules. ,− Others, especially Hansma, Bustamante, and Henderson, have studied isolated proteins ,− or DNA molecules ,− and their complexes .…”

Section: Introductionmentioning

confidence: 99%

Imaging the Molecular Dimensions and Oligomerization of Proteins at Liquid/Solid Interfaces

et al. 1998

View full text Add to dashboard Cite

Individual Concanavalin A (ConA) molecules have been imaged at the liquid/solid interface with an atomic force microscope (AFM). Three-dimensional sizing with very high resolution (<5 Å) has been obtained by a novel approach based on height distributions, which avoids the tip convolution effects which normally affect scanning probe microscopy techniques. Each height measurement correlates to a particular molecular orientation on the surface. A large number of such measurements provide a statistical ensemble of orientations. The complete height distribution reflects the three-dimensional size of the protein sample and hence its tertiary and quaternary structure. A surface adsorption and orientation model, based on a minimization of surface adsorption energy, is proposed. This model is in good agreement with the observed height distribution of Con A molecules at the liquid/solid interface. Analysis of Con A and succinylated Con A molecules on mica demonstrates that Con A dimers are the prevalent species at the liquid/solid interface. This is in contrast to the tetrameric organization of Con A normally observed in solution. The new possibilities opened by height distribution analysis on the physical characterization of biomolecules at interfaces are also discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Imaging the Molecular Dimensions and Oligomerization of Proteins at Liquid/Solid Interfaces

et al. 1998

View full text Add to dashboard Cite

show abstract

“…The scanning probe microscopies have proven invaluable as surface characterization tools to an impressive range of fundamental and technological areas. − We have, in parallel with the efforts of others, − been exploring the use of the friction and adhesion modes of scanning force microscopy (SFM) as probes of the compositional transformations of interfaces at nanometer length scales. , While continuing such investigations, we have discovered that the mechanical interaction between a SFM probe tip and various ester-functionalized alkanethiolate monolayers can notably accelerate the rate of the base hydrolysis of the ester linkage in small, spatially defined locations. The following describes our initial findings using monolayers chemisorbed at Au(111) from dithiobis(succinimido undecanoate) (DSU).…”

Section: Introductionmentioning

confidence: 99%

SFM Tip-Assisted Hydrolysis of a Dithiobis(succinimido undecanoate) Monolayer Chemisorbed on a Au(111) Surface

et al. 1997

View full text Add to dashboard Cite

This paper reports on the use of a scanning force microscope (SFM) for the tip-assisted base hydrolysis of an ester-terminated alkanethiolate monolayer on Au(111). We have found that contact imaging accelerates the base hydrolysis of a dithiobis(succinimido undecanoate) monolayer relative to the surrounding unimaged area. It is proposed that (1) the mechanical disruption by the SFM probe tip of the steric barrier imposed by the neighboring adsorbates facilitates access of hydroxide ions to the buried acyl carbons in the adlayer, and (2) the surface area hydrolytically transformed by this disruption can be controlled by the SFM imaging conditions. Findings in support of our conclusions are presented, and potential implications to nanotechnology are briefly discussed.

show abstract

“…The primary basis for adsorption patterns in vacuum or air is imaging of small and intermediate-size adsorbate molecules with molecular and submolecular resolution (14)(15)(16)(17), combined with theoretical frames for tunneling through adsorbate molecules based on different methodologies (17)(18)(19)(20)(21). There are also reported experimental approaches to functional mapping of intermediate-size molecules, most prominently in the form of correlations between the tunnel current and the bias voltage.…”

mentioning

confidence: 99%

An approach to long-range electron transfer mechanisms in metalloproteins: In situ scanning tunneling microscopy with submolecular resolution

Friis

Andersen

Kharkats

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

131

106

View full text Add to dashboard Cite

In situ scanning tunneling microscopy (STM) of redox molecules, in aqueous solution, shows interesting analogies and differences compared with interfacial electrochemical electron transfer ( Molecular long-range electron transfer (ET) in solid phases or liquid solution, in which the ET distance exceeds the structural extension of the donor and acceptor, has been in focus over the last decade and a half (1-5). Progress has rested on synthetic donor-acceptor molecules (1-3), metalloproteins (2, 4, 6, 7), and on new electrochemical systems in which electrons are brought to tunnel across well characterized, self-assembled films (8, 9). These achievements have prompted new theoretical efforts with notions such as directional tunneling along chemical bond networks (10), fluctuating tunnel barriers (11, 12), coherent and resonance ET (13), and self-consistent electronic-vibrational interaction (11).In a parallel development, scanning tunneling and atomic force microscopy (STM and AFM, respectively) have opened exciting new perspectives for mapping molecular adsorbate patterns (14, 15). The primary basis for adsorption patterns in vacuum or air is imaging of small and intermediate-size adsorbate molecules with molecular and submolecular resolution (14-17), combined with theoretical frames for tunneling through adsorbate molecules based on different methodologies (17-21). There are also reported experimental approaches to functional mapping of intermediate-size molecules, most prominently in the form of correlations between the tunnel current and the bias voltage. Target adsorbates for ex situ STM imaging have been, for example, benzene (22, 23), methylazulenes (17, 24), C 60 (25), alkyl and aryl thiolates (17,21,(26)(27)(28), and transition metal phthalocyanins (29) on highly oriented pyrolytic graphite or crystalline surfaces of electronically ''soft'' metals compatible with the adsorbates. STM imaging at the solid͞air interface to molecular and occasionally submolecular resolution also has been extended to biological macromolecules including DNA (30) and a number of redox and nonredox proteins (for an overview, see ref. 31). Functional properties addressed particularly have been the electrical potential distribution and conductivity patterns of the tunnel gap (21, 27-29), resonance tunneling via suitable highest occupied molecular orbitals, lowest unoccupied molecular orbitals, or (transition metal) redox levels (17-21), and the notion of orbital-specific mediation of the tunnel current (29).Combination of STM with concepts of long-range ET in chemical and, particularly, metalloprotein systems must, however, give explicit attention to the fact that the natural medium for most chemical and biological reactivity is aqueous solution. Extension of STM͞AFM to aqueous solution (in situ STM͞ AFM) is established (32, 33) but has raised issues related to adsorbate immobilization, ultrapure solutions, tip coating, independent tip and substrate potential control (32-34), and the fundamental STM and AFM phenomena. In situ...

show abstract

Scanning Probe Microscopy

Cited by 26 publications

References 325 publications

Imaging the Molecular Dimensions and Oligomerization of Proteins at Liquid/Solid Interfaces

Imaging the Molecular Dimensions and Oligomerization of Proteins at Liquid/Solid Interfaces

SFM Tip-Assisted Hydrolysis of a Dithiobis(succinimido undecanoate) Monolayer Chemisorbed on a Au(111) Surface

An approach to long-range electron transfer mechanisms in metalloproteins: In situ scanning tunneling microscopy with submolecular resolution

Contact Info

Product

Resources

About