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.

scholarly journals Microfluidic Impedance Biosensor Chips Using Sensing Layers Based on DNA-Based Self-Assembled Monolayers for Label-Free Detection of Proteins

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 80
Author(s):  
Khaled Alsabbagh ◽  
Tim Hornung ◽  
Achim Voigt ◽  
Sahba Sadir ◽  
Taleieh Rajabi ◽  
...  
Keyword(s):  
Troponin I ◽  
Electrochemical Impedance ◽  
Specific Binding ◽  
Self Assembled Monolayers ◽  
Significant Shift ◽  
Label Free ◽  
Label Free Detection ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Biosensor Chip

A microfluidic chip for electrochemical impedance spectroscopy (EIS) is presented as bio-sensor for label-free detection of proteins by using the example of cardiac troponin I. Troponin I is one of the most specific diagnostic serum biomarkers for myocardial infarction. The microfluidic impedance biosensor chip presented here consists of a microscope glass slide serving as base plate, sputtered electrodes, and a polydimethylsiloxane (PDMS) microchannel. Electrode functionalization protocols were developed considering a possible charge transfer through the sensing layer, in addition to analyte-specific binding by corresponding antibodies and reduction of nonspecific protein adsorption to prevent false-positive signals. Reagents tested for self-assembled monolayers (SAMs) on gold electrodes included thiolated hydrocarbons and thiolated oligonucleotides, where SAMs based on the latter showed a better performance. The corresponding antibody was covalently coupled on the SAM using carbodiimide chemistry. Sampling and measurement took only a few minutes. Application of a human serum albumin (HSA) sample, 1000 ng/mL, led to negligible impedance changes, while application of a troponin I sample, 1 ng/mL, led to a significant shift in the Nyquist plot. The results are promising regarding specific detection of clinically relevant concentrations of biomarkers, such as cardiac markers, with the newly developed microfluidic impedance biosensor chip.

Formation and stability of porphyrin and phthalocyanine self-assembled monolayers on ZnO surfaces

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1264-1271 ◽  
Author(s):  
Hanna Hakola ◽  
Essi Sariola-Leikas ◽  
Paavo Jäntti ◽  
Thomas Mokus ◽  
Kati Stranius ◽  
...  
Keyword(s):  
Thin Films ◽  
Zno Nanorods ◽  
Self Assembled Monolayers ◽  
Layer Formation ◽  
Zno Film ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Anchoring Groups ◽  
The Stability ◽  
Phosphate Groups

Formation of self-assembled monolayers (SAMs) of three porphyrin and one phthalocyanine derivatives on thin ZnO film was studied by monitoring absorption spectra of the samples. The compounds were equipped with carboxylic or phosphate groups to bind to the surface. The SAM formation was found to be fast. The layer was formed in less than 15 min for all studied porphyrins, and 30 min was sufficient to form phthalocyanine layer. For porphyrins with different anchor groups the SAM formation was too fast to see any difference between the anchoring groups. The stability of SAMs was tested then by immersing the samples into neat solvents. Upon immersion the SAMs were gradually losing the absorbance for all the compounds with degradation trends being in line with p[Formula: see text] values of the binding groups of the same type. However, even for the weakest binding group the SAM was relatively stable after a few tens of minutes of washing, which was sufficient to remove physisorbed compounds but the SAM was essentially not destroyed. Comparison of SAMs on thin films with SAMs on ZnO nanorods and TiO2 nanoparticle films indicated the same fast layer formation but relatively weaker SAMs stability, showing 20–40% faster absorption losses during the washing.

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.

scholarly journals Perfluorinated Self-Assembled Monolayers Enhance the Stability and Efficiency of Inverted Perovskite Solar Cells

ACS Nano ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 1445-1456 ◽  
Author(s):  
Christian M. Wolff ◽  
Laura Canil ◽  
Carolin Rehermann ◽  
Nguyen Ngoc Linh ◽  
Fengshuo Zu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
The Stability

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.

Controlling the Surface Reactivity of Titania via Electronic Tuning of Self-Assembled Monolayers

ACS Catalysis ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. 8351-8357 ◽  
Author(s):  
Lucas D. Ellis ◽  
Ryan M. Trottier ◽  
Charles B. Musgrave ◽  
Daniel K. Schwartz ◽  
J. Will Medlin
Keyword(s):  
Surface Reactivity ◽  
Self Assembled Monolayers ◽  
Electronic Tuning ◽  
Assembled Monolayers ◽  
Self Assembled

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.

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