Revealing molecular-level surface structure of amyloid fibrils in liquid by means of frequency modulation atomic force microscopy

Fukuma, Takeshi; Mostaert, Anika S.; Serpell, Louise C.; Jarvis, Suzanne P.

doi:10.1088/0957-4484/19/38/384010

Cited by 41 publications

(30 citation statements)

References 29 publications

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“…The biomolecular assemblies, amyloid fibrils, are also imaged in liquid, showing the arrangements of individual ␤-strands at Ångstrom resolution. 16 These results demonstrated the applicability of low-noise FM-AFM to molecular-scale investigations of biological systems. After those previous works, the present study is aimed at resolving the remaining design issues.…”

Section: Introductionmentioning

confidence: 63%

Wideband low-noise optical beam deflection sensor with photothermal excitation for liquid-environment atomic force microscopy

Fukuma

2009

Review of Scientific Instruments

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I developed a wideband low-noise optical beam deflection sensor with a photothermal cantilever excitation system for liquid-environment atomic force microscopy. The developed sensor has a 10 MHz bandwidth and 4.7 fm/ ͱ Hz deflection noise density in water. The theoretically limited noise performance ͑i.e., the noise level limited only by the photodiode shot noise͒ has been achieved in liquid for the first time. Owing to the wide bandwidth and the replaceable focus lens design, the sensor is applicable to cantilevers with various dimensions. The deflection noise densities of less than 7.8 fm/ ͱ Hz have been achieved in water for cantilevers with lengths from 35 to 125 m. The ideal amplitude and phase versus frequency curves without distortion are obtained with the developed photothermal excitation system. The excitation system is applicable to relatively stiff cantilevers ͑Ͼ20 N / m͒ in liquid, making it possible to obtain true atomic-resolution images in liquid. True atomic-resolution imaging of mica in water is demonstrated using the developed deflection sensor and the photothermal excitation system.

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Section: Introductionmentioning

confidence: 63%

Wideband low-noise optical beam deflection sensor with photothermal excitation for liquid-environment atomic force microscopy

Fukuma

2009

Review of Scientific Instruments

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124

122

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“…(e), (f) The frequency spectral density distributions of the ∆f versus distance curves (raw data). The dotted lines correspond to n f B values calculated from equation (11). Note that these calculated values are multiplied by a correction factor Q * d /Q * for the same reason as described above.…”

Section: Measurements Of Hydration Forcesmentioning

confidence: 99%

“…Equation (10) describing F min is obtained by taking the ratio of n fB divided by S f . While n fB is given by equation (11), S f is given by…”

Section: Measurements Of Hydration Forcesmentioning

confidence: 99%

Atomic-resolution imaging in liquid by frequency modulation atomic force microscopy using small cantilevers with megahertz-order resonance frequencies

et al. 2012

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Abstract. In this study, we have investigated the performance of liquid-environment FM-AFM with various cantilevers having different dimensions from theoretical and experimental aspects. The results show that the reduction of the cantilever dimensions provides improvement in the minimum detectable force as long as the tip height is sufficiently long compared with the width of the cantilever. However, we also found two important issues to be overcome to achieve this theoretically-expected performance. The stable photothermal excitation of a small cantilever requires much higher pointing stability of an excitation laser beam than that for a long cantilever. We present a way to satisfy this stringent requirement using a temperature controlled laser diode module and a polarization-maintaining optical fiber. Another issue is associated with the tip. While a small carbon tip formed by electron beam deposition (EBD) is desirable for small cantilevers, we found that an EBD tip is not suitable for atomic-scale applications due to the weak tip-sample interaction. Here we present that the tip-sample interaction can be greatly enhanced by coating the tip with Si. With these improvements, we demonstrate atomic-resolution imaging of mica in liquid using a small cantilever with a megahertz-order resonance frequency. In addition, we experimentally demonstrate the improvement in the minimum detectable force obtained by the small cantilever in the measurements of oscillatory hydration forces.

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“…Examples of the early applications include minerals [12,[14][15][16] and biological systems [14,[17][18][19][20][21][22]. While these results highlighted the high spatial resolution and wide applicability of liquid-environment FM-AFM, they also clarified its fundamental limitation.…”

Section: Introductionmentioning

confidence: 99%

Advanced Instrumentation of Frequency Modulation AFM for Subnanometer-Scale 2D/3D Measurements at Solid-Liquid Interfaces

Fukuma

2015

Noncontact Atomic Force Microscopy

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Since the first demonstration of true atomic-resolution imaging by frequency modulation atomic force microscopy (FM-AFM) in liquid, the method has been used for imaging subnanometer-scale structures of various materials including minerals, biological systems and other organic molecules. Rencetly, there have been further advancements in the FM-AFM instrumentation. Three-dimensional (3D) force measurement techniques are proposed for visualizing 3D hydration structures formed at a solid-liquid interface. These methods further enabled to visualize 3D distributions of flexible surface structures at interfaces between soft materials and water. Furthermore, the fundamental performance such as force sensitivity and operation speed have been significantly improved using a small cantilever and highspeed phase detector. These technical advancements enabled direct visualization of atomic-scale interfacial phenomena at 1 frame/sec. In this chapter, these recent advancements in the FM-AFM instrumentation and their applications to the studies on various interfacial phenomena are presented.

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Revealing molecular-level surface structure of amyloid fibrils in liquid by means of frequency modulation atomic force microscopy

Cited by 41 publications

References 29 publications

Wideband low-noise optical beam deflection sensor with photothermal excitation for liquid-environment atomic force microscopy

Wideband low-noise optical beam deflection sensor with photothermal excitation for liquid-environment atomic force microscopy

Atomic-resolution imaging in liquid by frequency modulation atomic force microscopy using small cantilevers with megahertz-order resonance frequencies

Advanced Instrumentation of Frequency Modulation AFM for Subnanometer-Scale 2D/3D Measurements at Solid-Liquid Interfaces

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