LVSEM for Biology

Pawley, James B.

doi:10.1007/978-0-387-72972-5_2

Cited by 17 publications

(9 citation statements)

References 121 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, for most of the cases, the brightness level is reverse. Cells appear darker than the MWCNTs due to the differences in cell surface density: cells density (∼0.25 g cm –3 ), which is around one order of magnitude lower than MWCNTs (∼2.6 g cm –3 ) (Pawley, ). All these contributing factors to SE yield maintain the mid‐level brightness, causing low contrast in neutralised surfaces.…”

Section: Discussionmentioning

confidence: 99%

Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence

Dykas

Poddar

Yoong

et al. 2017

Journal of Microscopy

View full text Add to dashboard Cite

Carbon nanotubes (CNTs) have become an important nano entity for biomedical applications. Conventional methods of their imaging, often cannot be applied in biological samples due to an inadequate spatial resolution or poor contrast between the CNTs and the biological sample. Here we report a unique and effective detection method, which uses differences in conductivities of carbon nanotubes and HeLa cells. The technique involves the use of a helium ion microscope to image the sample with the surface charging artefacts created by the He and neutralised by electron flood gun. This enables us to obtain a few nanometre resolution images of CNTs in HeLa Cells with high contrast, which was achieved by tailoring the He fluence. Charging artefacts can be efficiently removed for conductive CNTs by a low amount of electrons, the fluence of which is not adequate to discharge the cell surface, resulting in high image contrast. Thus, this technique enables rapid detection of any conducting nano structures on insulating cellular background even in large fields of view and fine spatial resolution. The technique demonstrated has wider applications for researchers seeking enhanced contrast and high-resolution imaging of any conducting entity in a biological matrix - a commonly encountered issue of importance in drug delivery, tissue engineering and toxicological studies.

show abstract

Section: Discussionmentioning

confidence: 99%

Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence

Dykas

Poddar

Yoong

et al. 2017

Journal of Microscopy

View full text Add to dashboard Cite

show abstract

“…This succeeds in shielding the adverse field effects of the buried charge back on to the primary beam and at the same time provides a conducting path that avoids the unstable buildup of charge. This is a common strategy for observing the biological, medical, and insulator specimens(Pawley, 2008), and is usually adequate for simple imaging applications. However, it does not prevent charge from being deposited into the insulator since the primary beam penetrates the top metal layer (usually only a few to tens of nanometers thick), nor does it provide any way for monitoring how much charge is being deposited into the insulator.…”

Section: Introductionmentioning

confidence: 99%

Secondary Electron Energy Contrast of Localized Buried Charge in Metal–Insulator–Silicon Structures

2018

View full text Add to dashboard Cite

This paper presents a new method for creating and monitoring controlled localized negatively charged regions inside insulators with a scanning electron microscope (SEM). A localized buried charged region is created and observed close to the point where a high voltage primary beam (10 kV) strikes a metal–insulator–silicon specimen. The amount of buried charge within the insulator at any given moment can be dynamically monitored by detecting the appearance of a second peak in the secondary electron (SE) energy spectrum. SE energy spectral signals were obtained through the use of a compact high signal-to-noise energy analyzer attachment that was fitted on to the SEM specimen stage. An electrostatic model, together with Monte Carlo simulations, is presented to explain how the SE charge contrast effect functions. This model is then experimentally confirmed by using the SE energy spectral signal induced by a gallium ion beam inside a dual focused ion beam-SEM instrument.

show abstract

“…Interior surfaces of vitrified samples are typically exposed by freeze fracture to reveal cellular ultrastructure (Pawley, 2008). The fracture surface can be imaged as is.…”

Section: Introductionmentioning

confidence: 99%

Large Area Cryo-Planing of Vitrified Samples Using Broad-Beam Ion Milling

Chang

Joester

2015

Microsc Microanal

View full text Add to dashboard Cite

On account of its excellent resolution and high throughput, cryoSEM imaging has recently seen resurgence. In this work, we report on the development of cryogenic triple ion gun milling (CryoTIGM™), a broad ion beam milling technique for cryo-planing of vitrified, "frozen-hydrated" specimens. We find that sections prepared with CryoTIGM™ are smooth over exceptionally large areas (~700,000 µm2), and reveal ultrastructural details in similar or better quality than freeze-fractured samples.

show abstract

LVSEM for Biology

Cited by 17 publications

References 121 publications

Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence

Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence

Secondary Electron Energy Contrast of Localized Buried Charge in Metal–Insulator–Silicon Structures

Large Area Cryo-Planing of Vitrified Samples Using Broad-Beam Ion Milling

Contact Info

Product

Resources

About