Site-Specific Attachment of Gold Nanoparticles to DNA Templates

2001 ◽  
Vol 635 ◽  
Author(s):  
Karen A. Stevenson ◽  
Govindarajan Muralidharan ◽  
Leon Maya ◽  
Jack C. Wells ◽  
Jacob Barhen
Keyword(s):  
Gold Nanoparticles ◽  
Amino Groups ◽  
Dna Templates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Carbodiimide Hydrochloride ◽  
Transmission Electron ◽  
Specific Attachment ◽  
Chemical Technique ◽  
Dna Template

AbstractDNA was used as a scaffold for the binding of gold nanoparticles using a standard chemical technique. A DNA template was designed with amino-modified thymines located every 3.7 nm, which would allow the attachment of the carboxylic acid functionalized gold nanoparticles. The gold particles were covalently bound to the amino groups on the DNA using standard 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) chemistry in the presence of a competitor to block excess gold binding sites. The products were analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM).

Nanoparticle Assembly via Hydrogen-Bonding: IRS, TEM and AFM Characterizations

2001 ◽  
Vol 635 ◽  
Author(s):  
Li Han ◽  
Mathew M. Maye ◽  
Chuan-Jian Zhong
Keyword(s):  
Gold Nanoparticles ◽  
Hydrogen Bonding ◽  
Morphological Properties ◽  
Nanoparticle Assembly ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Infrared Reflection ◽  
Afm Imaging ◽  
Infrared Reflection Spectroscopy

AbstractThis paper reports results of the characterizations of nanoparticle assembly formed via spontaneous core-shell and shell-shell reactivities at thiolate-capped gold nanoparticles. Gold nanoparticles of two different core sizes and thiols with carboxylic acid terminals are exploited as a model system. The reactivities involve covalent Au-thiolate bonding and non-covalent hydrogen-bonding with anisotropic linking character. We employed infrared reflection spectroscopy (IRS), atomic force microscopy (AFM) and transmission electron microscopy (TEM) for the characterizations. While IRS provides structural assessment, TEM and AFM imaging measurements probe the morphological properties.

scholarly journals Caffeic Acid: Potential Applications in Nanotechnology as a Green Reducing Agent for Sustainable Synthesis of Gold Nanoparticles

2015 ◽  
Vol 10 (4) ◽  
pp. 1934578X1501000
Author(s):  
Yu Seon Seo ◽  
Song-Hyun Cha ◽  
Seonho Cho ◽  
Hye-Ran Yoon ◽  
Young-Hwa Kang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Caffeic Acid ◽  
Average Diameter ◽  
Reducing Agent ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Potential Applications ◽  
Acid Potential ◽  
Sustainability Initiatives

The sustainable synthesis of gold nanoparticles from gold ions was conducted with caffeic acid as a green reducing agent. The formation of gold nanoparticles was confirmed by spectroscopic and microscopic methods. Spherical nanoparticles with an average diameter of 29.99 ± 7.43 nm were observed in high-resolution transmission electron microscopy and atomic force microscopy images. The newly prepared gold nanoparticles exhibited catalytic activity toward the reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride. This system enables the preparation of green catalysts using plant natural products as reducing agents, which fulfills the growing need for sustainability initiatives.

scholarly journals Nanoengineering of Gold Nanoparticles: Green Synthesis, Characterization, and Applications

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 612 ◽  
Author(s):  
Nancy Tepale ◽  
Víctor V. A. Fernández-Escamilla ◽  
Clara Carreon-Alvarez ◽  
Valeria J. González-Coronel ◽  
Adan Luna-Flores ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Fundamental Study ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Transmission Electron

The fundamental aspects of the manufacturing of gold nanoparticles (AuNPs) are discussed in this review. In particular, attention is devoted to the development of a simple and versatile method for the preparation of these nanoparticles. Eco-friendly synthetic routes, such as wet chemistry and biosynthesis with the aid of polymers, are of particular interest. Polymers can act as reducing and/or capping agents, or as soft templates leading to hybrid nanomaterials. This methodology allows control of the synthesis and stability of nanomaterials with novel properties. Thus, this review focus on a fundamental study of AuNPs properties and different techniques to characterize them, e.g., Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), UV-Visible spectroscopy, Dynamic Light Scattering (DLS), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy, Small-angle X-Ray Scattering (SAXS), and rheology. Recently, AuNPs obtained by “green” synthesis have been applied in catalysis, in medicine, and as antibacterials, sensors, among others.

scholarly journals Enzyme-Free Electrochemical Nano-Immunosensor Based on Graphene Quantum Dots and Gold Nanoparticles for Cardiac Biomarker Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 578
Author(s):  
Bhargav D. Mansuriya ◽  
Zeynep Altintas
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Gold Nanoparticles ◽  
Troponin I ◽  
Electrochemical Techniques ◽  
Graphene Quantum Dots ◽  
High Specificity ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

An ultrasensitive enzyme-free electrochemical nano-immunosensor based on a screen-printed gold electrode (SPGE) modified with graphene quantum dots (GQDs) and gold nanoparticles (AuNPs) was engineered to detect cardiac troponin-I (cTnI) for the early diagnosis of acute myocardial infarction (AMI). The GQDs and in-house synthesized AuNPs were implanted onto the SPGE and allowed for anti-cTnI immobilization prior to quantifying cTnI. The biomarker could be determined in a wide concentration range using square-wave voltammetry (SWV), cyclic voltammetry (CV), electron impedance spectroscopy (EIS) and amperometry. The analyses were performed in buffer, as well as in human serum, in the investigation ranges of 1–1000 and 10–1000 pg mL−1, respectively. The detection time ranged from 10.5–13 min, depending on the electrochemical method employed. The detection limit was calculated as 0.1 and 0.5 pg mL−1 for buffer and serum, respectively. The sensitivity of the immunosensor was found to be 6.81 µA cm−2 pg mL−1, whereas the binding affinity was determined to be <0.89 pM. The sensor showed high specificity for cTnI with slight responses for nonspecific biomolecules. Each step of the sensor fabrication was characterized using CV, SWV, EIS and atomic force microscopy (AFM). Moreover, AuNPs, GQDs and their nanocomposites were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). This is the first immunosensor that represents the successful determination of an analyte using four different electrochemical techniques. Such a sensor could demonstrate a promising future for on-site detection of AMI with its sensitivity, cost-effectiveness, rapidity and specificity.

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

The Electrical Characterization and Physical Failure Analysis for Transistor Gate Leakage

2006 ◽  
Author(s):  
Tsung-Te Li ◽  
Chao-Chi Wu ◽  
Jung-Hsiang Chuang ◽  
Jon C. Lee
Keyword(s):  
Failure Analysis ◽  
Electrical Characterization ◽  
Physical Analysis ◽  
Gate Leakage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Voltage Stress ◽  
Leakage Site

Abstract This article describes the electrical and physical analysis of gate leakage in nanometer transistors using conducting atomic force microscopy (C-AFM), nano-probing, transmission electron microscopy (TEM), and chemical decoration on simulated overstressed devices. A failure analysis case study involving a soft single bit failure is detailed. Following the nano-probing analysis, TEM cross sectioning of this failing device was performed. A voltage bias was applied to exaggerate the gate leakage site. Following this deliberate voltage overstress, a solution of boiling 10%wt KOH was used to etch decorate the gate leakage site followed by SEM inspection. Different transistor leakage behaviors can be identified with nano-probing measurements and then compared with simulation data for increased confidence in the failure analysis result. Nano-probing can be used to apply voltage stress on a transistor or a leakage path to worsen the weak point and then observe the leakage site easier.

Structural and Optical Properties of InAsSbBi Grown by Molecular Beam Epitaxy on Offcut GaSb Substrates

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 215
Author(s):  
Rajeev R. Kosireddy ◽  
Stephen T. Schaefer ◽  
Marko S. Milosavljevic ◽  
Shane R. Johnson
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optical Quality ◽  
X Ray Diffraction ◽  
Interface Quality ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Lateral Variations

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.

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