Self-assembly of biomolecules at surfaces characterized by NEXAFS

2007 ◽  
Vol 85 (10) ◽  
pp. 793-800 ◽  
Author(s):  
Xiaosong Liu ◽  
Fan Zheng ◽  
A Jürgensen ◽  
V Perez-Dieste ◽  
D Y Petrovykh ◽  
...  
Keyword(s):  
Surface Science ◽  
Self Assembly ◽  
Ribonuclease A ◽  
Polarization Dependence ◽  
Biological Molecules ◽  
Self Assembled Monolayers ◽  
Peptide Bonds ◽  
Molecular Adsorbates ◽  
Dna Oligonucleotides ◽  
Assembled Monolayers

Surface science has made great strides towards tailoring surface properties via self-assembly of nanoscale molecular adsorbates. It is now possible to functionalize surfaces with complex biomolecules such as DNA and proteins. This brief overview shows how NEXAFS (near edge X-ray absorption fine structure spectroscopy) can be used to characterize the assembly of biological molecules at surfaces in atom- and orbital-specific fashion. To illustrate the range of applications, we begin with simple self-assembled monolayers (SAMs), proceed to SAMs with customized terminal groups, and finish with DNA oligonucleotides and Ribonuclease A, a small protein containing 124 amino acids. The N 1s absorption edge is particularly useful for characterizing DNA and proteins because it selectively interrogates the π* orbitals in nucleobases and the peptide bonds in proteins. Information about the orientation of molecular orbitals is obtained from the polarization dependence. Quantitative NEXAFS models explain the polarization dependence in terms of molecular orientation and structure.Key words: NEXAFS, bio-interfaces, ribonuclease A, immobilization, orientation.

Stochastic Computing via In Operando Modulation of Rectification in Molecular Tunneling Junctions

2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi
Keyword(s):  
Self Assembly ◽  
Variable Temperature ◽  
Self Assembled Monolayers ◽  
Microfluidic Channels ◽  
Proof Of Concept ◽  
Glycol Ethers ◽  
Stochastic Computing ◽  
Assembled Monolayers ◽  
In Operando ◽  
Tunneling Junctions

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.

Self Assembled Monolayers and Carbon Nanotubes: A Significant Tool’s for Modification of Electrode Surface

2020 ◽  
Vol 18 (9) ◽  
pp. 669-685
Author(s):  
Padmaker Pandey ◽  
Anamika Pandey ◽  
Shruti Singh ◽  
Nikhil Kant Shukla
Keyword(s):  
Carbon Nanotubes ◽  
Volume Ratio ◽  
Biological Molecules ◽  
Self Assembled Monolayers ◽  
Self Assembling ◽  
Biological Surfaces ◽  
Biological Recognition ◽  
Monomolecular Films ◽  
Assembled Monolayers ◽  
Interfacial Surfaces

A compromising and well-organized model system is needed for investigating the molecular behaviour of biomolecules as many transduction processes and biological recognition occur at biological surfaces. The application of techniques in interfacial surfaces like one molecule thick films has made a feasible and significant tool for modern scientific studies. Self Assembling Monolayers (SAMs) technology is a very useful means for producing monomolecular films of various biological molecules on different substrates. Carbon Nanotubes (CNTs) have length-to-diameter aspect ratio property which provides a large surface-to-volume ratio, making it an intensely capable material for biomolecular attachments. The incorporation of Carbon Nanotubes (CNTs) with biological systems forming functional assemblies has shown an explored area of research. Organo-sulfur mainly alkanethiol (CnH2n+1–SH) molecules get adsorbed onto CNTs. This phenomenon has grabbed a lot of attention because Self Assembling Monolayers (SAMs) of organo-sulfur compound acts as an example system for understanding important chemical, physical or biological processes.

Synthesis of Silver Nanoparticles with Monovalently Functionalized Self-Assembled Monolayers

2012 ◽  
Vol 65 (3) ◽  
pp. 275 ◽  
Author(s):  
P. Free ◽  
D. Paramelle ◽  
M. Bosman ◽  
J. Hobley ◽  
D. G. Fernig
Keyword(s):  
Silver Nanoparticles ◽  
Specific Binding ◽  
Nitrilotriacetic Acid ◽  
Surface Reactivity ◽  
Biological Molecules ◽  
Peptide Sequence ◽  
Self Assembled Monolayers ◽  
Ligand Shell ◽  
Assembled Monolayers ◽  
The Stability

The importance of having nanoparticles that are soluble, stable, and that have no non-specific binding is often overlooked, but essential for their use in biology. This is particularly prominent with silver nanoparticles that are susceptible to the effects of aggregation and metal-surface reactivity. Here we use a combination of several small peptidols and short alkanethiol ethylene glycol ligands to develop a ligand shell that is reasonably resistant to ligand exchange and non-specific binding to groups common in biological molecules. The stability of the nanoparticles is not affected by the inclusion of a functional ligand, which is done in the same preparative step. The stoichiometry of the nanoparticles is controlled, such that monofunctional silver nanoparticles can be obtained. Two different sets of nanoparticles, functionalized with either Tris-nitrilotriacetic acid or a hexa-histidine peptide sequence, readily form dimers/oligomers, depending on their stoichiometry of functionalization.

Selective choline biosensors based on choline oxidase co-immobilized into self-assembled monolayers on micro-chips at low potential

2015 ◽  
Vol 7 (22) ◽  
pp. 9426-9434 ◽  
Author(s):  
Mohammed M. Rahman ◽  
Abdullah M. Asiri
Keyword(s):  
Choline Oxidase ◽  
Biological Molecules ◽  
Selective Recognition ◽  
Self Assembled Monolayers ◽  
Buffer System ◽  
Assembled Monolayers ◽  
Self Assembled

The fabricated choline-biosensor exhibits excellent specific and selective recognition for selected biological molecules coexisting with interferents in a buffer system at low potential.

Synthesis of Calixarene Derivatives in One Reaction System

2014 ◽  
Vol 1015 ◽  
pp. 594-597
Author(s):  
Bing Qing Cao ◽  
Qi Bin Huang ◽  
Yong Pan ◽  
Mo Lin Qin
Keyword(s):  
Self Assembly ◽  
Delay Line ◽  
Organophosphorus Compounds ◽  
Reaction System ◽  
Reference Value ◽  
Self Assembled Monolayers ◽  
Sensitive Film ◽  
Assembled Monolayers ◽  
Ft Ir ◽  
Substitute Reaction

This paper presents a effective approach for one new supermolecule function materia preparation, 25-(thioalkyl-alkoxy)-p-tertbutylcalix [4] arene with self-assembled monolayers character was synthesized by two-step nucleophilic substitute reaction in NaH-THF phase with p-tertbutylcalix [4] arene and dibromodecne . The structure of product was characterized by FT-IR, 1H NMR, 13C NMR and MALDI-TOF-MS. The self-assembly molecular imprinted film as the sensitive film was coated on the gold delay line of SAW sensors to detect for detecting organophosphorus compounds such as sarin, had important reference value in counter-terrorism.

scholarly journals Surface assembly and nanofabrication of 1,1,1-tris(mercaptomethyl)heptadecane on Au(111) studied with time-lapse atomic force microscopy

2014 ◽  
Vol 5 ◽  
pp. 26-35 ◽  
Author(s):  
Tian Tian ◽  
Burapol Singhana ◽  
Lauren E Englade-Franklin ◽  
Xianglin Zhai ◽  
T Randall Lee ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Self Assembly ◽  
Time Lapse ◽  
Scanning Probe ◽  
Self Assembled Monolayers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Assembly ◽  
Assembled Monolayers ◽  
Liquid Cell

The solution self-assembly of multidentate organothiols onto Au(111) was studied in situ using scanning probe nanolithography and time-lapse atomic force microscopy (AFM). Self-assembled monolayers (SAMs) prepared from dilute solutions of multidentate thiols were found to assemble slowly, requiring more than six hours to generate films. A clean gold substrate was first imaged in ethanolic media using liquid AFM. Next, a 0.01 mM solution of multidentate thiol was injected into the liquid cell. As time progressed, molecular-level details of the surface changes at different time intervals were captured by successive AFM images. Scanning probe based nanofabrication was accomplished using protocols of nanografting and nanoshaving with n-alkanethiols and a tridentate molecule, 1,1,1-tris(mercaptomethyl)heptadecane (TMMH). Nanografted patterns of TMMH could be inscribed within n-alkanethiol SAMs; however, the molecular packing of the nanopatterns was less homogeneous compared to nanopatterns produced with monothiolates. The multidentate molecules have a more complex assembly pathway than monothiol counterparts, mediated by sequential steps of forming S–Au bonds to the substrate.

scholarly journals Development of an Enzyme-Coated Microcantilever-Based Biosensor for Specific Detection of Short-Chain Alcohols

2021 ◽  
Vol 6 (1) ◽  
pp. 75
Author(s):  
Alexandre Margarido ◽  
Livia Regina Manzine ◽  
Fernando M. Araujo-Moreira ◽  
Renato Vitalino Gonçalves ◽  
Paulo Sergio de Paula Herrmann
Keyword(s):  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Short Chain ◽  
Self Assembled Monolayers ◽  
Specific Detection ◽  
Force Microscopy ◽  
Nonpolar Solvents ◽  
Atomic Force ◽  
Assembled Monolayers ◽  
Enzymatic Detection

This paper describes the development of a biosensor designed for the enzymatic detection of short-chain alcohols. The biorecognition element, alcohol dehydrogenase, was immobilized on self-assembled monolayers deposited on top of silicon nitride microcantilevers. The self-assembly process was performed by surface activation using 3-aminopropyltriethoxysilane, followed by glutaraldehyde and biomolecule binding. X-ray photoelectron spectroscopy and atomic force microscopy were used. The biosensor showed a lower response time and sensibility from 0.03 to 1.2 mL/L. Its selectivity was analyzed through exposure to pure and mixed volatile solvents. Sensor sensibility was higher in the presence of short-chain alcohols and practically null involving other polar or nonpolar solvents.

Self-Assembled Patterning of Ultrathin Silicides by Local Oxidation

MRS Bulletin ◽  
1999 ◽  
Vol 24 (8) ◽  
pp. 31-35 ◽  
Author(s):  
S. Mantl ◽  
Q.T. Zhao ◽  
B. Kabius
Keyword(s):  
Self Assembly ◽  
Vertical Direction ◽  
Self Assembled Monolayers ◽  
X Rays ◽  
Precise Control ◽  
Spacer Layer ◽  
Local Oxidation ◽  
Assembled Monolayers ◽  
Alternative Approaches ◽  
Self Assembled

Most microfabrication techniques employ masks to transfer the desired microstructure onto a wafer using ultraviolet light, x-rays, electrons, or ions for the projection of the structures. Generally, photoresist processing and etching follow to form the final structures. In all cases, the facilities necessary to perform these processes grow increasingly more complex as the feature size of the structures diminishes, and these processes face their practical or economic limits at dimensions of about 50 nm. Thus alternative approaches are under investigation, including different self-assembly techniques. They require no costly facilities and no masks with nanometer structures, and they promise high throughput, since the patterning is directly achieved by a physical or chemical process. Self-assembled monolayers of long-chain organic molecules are the most widely studied examples, where chemisorption and spontaneous self-ordering of the molecules are observed on appropriate substrates. Another interesting example is island-ordering, laterally or in a vertical direction, during epitaxial growth. The lattice-mismatched islands tend to nucleate preferentially on top of each other when separated by a thin spacer layer, due to the associated strain field. Another approach is the use of specific stressor layers on the surface to obtain alignment of buried precipitates along the stressor lines. However, the main challenges of all self-assembly techniques are precise control of the dimensions of the structures and reproducibility.

scholarly journals STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

2011 ◽  
Vol 2 ◽  
pp. 674-680 ◽  
Author(s):  
Tibor Kudernac ◽  
Natalia Shabelina ◽  
Wael Mamdouh ◽  
Sigurd Höger ◽  
Steven De Feyter
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembly Process ◽  
Organic Monolayers ◽  
Preferential Adsorption ◽  
Scanning Tunnelling ◽  
Assembled Monolayers ◽  
Tunnelling Microscopy ◽  
Self Assembled

Despite their importance in self-assembly processes, the influence of charged counterions on the geometry of self-assembled organic monolayers and their direct localisation within the monolayers has been given little attention. Recently, various examples of self-assembled monolayers composed of charged molecules on surfaces have been reported, but no effort has been made to prove the presence of counterions within the monolayer. Here we show that visualisation and exact localisation of counterions within self-assembled monolayers can be achieved with scanning tunnelling microscopy (STM). The presence of charges on the studied shape-persistent macrocycles is shown to have a profound effect on the self-assembly process at the liquid–solid interface. Furthermore, preferential adsorption was observed for the uncharged analogue of the macrocycle on a surface.

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