Nanowire Modification to Enhance the Performance of Neurotransmitter Sensors

2010 ◽  
Vol 1 (4) ◽  
Author(s):  
Hung Cao ◽  
J.-C. Chiao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Sensors ◽  
Electrochemical Sensing ◽  
Human Central Nervous System ◽  
Excitatory Neurotransmitter ◽  
Modification Method ◽  
Solid Liquid ◽  
Scanning Electron ◽  
Si Wafer

In this work, we have developed a method to modify the platinum (Pt) working electrode with nanowires using vapor-solid-liquid (VLS) mechanism in order to increase the sensitivity of our microelectrochemical neurotransmitter sensors. Our sensor probes were manufactured from a 300 μm thick silicon (Si) wafer with several electrode designs for implantation in various locations of the human central nervous system. The surfaces of electrodes were observed and characterized by scanning electron microscopy (SEM) and cyclic voltammetry (CV). The complete devices were made and used to demonstrate the enhancement in performance contributed by nanowires in the enzyme-based electrochemical sensing of L-glutamate, which is the most abundant excitatory neurotransmitter. Comparison between electrodes with and without nanowire modification was conducted, showing that the modification method is a good option to improve the performance of electrochemical sensors.

Fabrication of Electrochemical Sensors Based on Nanostructured Titanium Dioxide Formed through Anodic Oxidation

2015 ◽  
Vol 245 ◽  
pp. 182-189 ◽  
Author(s):  
Nikolai B. Kondrikov ◽  
Antonina S. Lapina ◽  
Ilya V. Stepanov ◽  
Galina I. Marinina ◽  
Vladimir V. Korochentsev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Dioxide ◽  
Anodic Oxidation ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Sensors ◽  
Structural Features ◽  
X Ray ◽  
Different Types ◽  
Scanning Electron

The nanotubular titanium dioxide structures were prepared using anodic oxidation. The structural features of surface have been investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS) techniques. These nanotubular titanium dioxide structures can be used as a sensor in potentiometric indication components of different types of chemical reactions.

Solid-Liquid Reaction for Synthesis of Rodlike Submicron Oxalate and the Thermolysis to Nanostrings of Co3O4 Nanobeads

2011 ◽  
Vol 233-235 ◽  
pp. 260-263
Author(s):  
Xian Da He ◽  
Hong Qi Ye ◽  
Qin Kuai ◽  
Kai Hua Xu ◽  
Hong Tao Han
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Liquid Reaction ◽  
Average Aspect Ratio ◽  
Cobalt Oxalate ◽  
Solid Liquid ◽  
Scanning Electron

A novel solid-liquid reaction route has been developed to synthesize rodlike submicron cobalt oxalate via dissolution of cobalt powders by oxalic acid. The rod diameter and length of the oxalate particles were found to be remarkably altered by using HCl or HNO3as additive. With HCl as additive rice-shaped particles were generated while with HNO3slender needlelike particles were created with an average aspect ratio up to 42. Furthermore, strings of Co3O4nanobeads were obtained by calcination of the slender precursor particles in air. The CoC2O4·2H2O submicron rods and Co3O4nanobeads were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TG), and X-ray diffraction (XRD).

The Study of Human Epithelium Cell Attachment to the Surface of Anode-Oxidized Titanium

2007 ◽  
Vol 342-343 ◽  
pp. 769-772
Author(s):  
Yao Wu ◽  
Bang Cheng Yang ◽  
Zhong Wei Gu ◽  
Xing Dong Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Attachment ◽  
Control Group ◽  
Epithelium Cell ◽  
Modification Method ◽  
Cultured Epithelium ◽  
Epithelium Cells ◽  
Scanning Electron

The achievement of biological sealing is determined by the quality of the skin attachment on the surface of the percutaneous implant in the area where the implant penetrates the skin. It has been known that certain surface features of the implants can significantly influence the interactions between cells and substrate. In this study, titanium plates were bioactivated through anode-oxidization firstly, and then cultured with human epithelium cells for 72h. Untreated Ti plates were used as control. After the samples were dehydrated, the morphology of the cultured epithelium cells was tested with Scanning electron microscopy (SEM). The surfaces of control group did not enhance epithelium cell attachment and growth, while the bioactivated microporous surface of anode-oxidized group would be beneficial to induce the formation of the pseudopod of epithelium cell, and then interlock the human epithelium cells through the pseudopod, which imply that the surface modification method of anode oxidization may be one of the most effective methods to resolve the biological sealing.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Microbulldozing and Microchiseling

1969 ◽  
Vol 27 ◽  
pp. 134-135
Author(s):  
J.N. Ramsey ◽  
D.P. Cameron ◽  
F.W. Schneider
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Material Handling ◽  
Microprobe Analysis ◽  
Foreign Matter ◽  
Specific Location ◽  
Potential Problems ◽  
Knoop Indenter ◽  
Scanning Electron ◽  
Microhardness Tester

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.

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