A5031297560- Force Microscopy Techniques and Applications
- Molecular Junctions and Nanostructures
- Polymer Surface Interaction Studies
- Nanofabrication and Lithography Techniques
- Near-Field Optical Microscopy
- Adhesion, Friction, and Surface Interactions
- Ion-surface interactions and analysis
- Mechanical and Optical Resonators
- Mass Spectrometry Techniques and Applications
- Advanced biosensing and bioanalysis techniques
- Gold and Silver Nanoparticles Synthesis and Applications
- Plasmonic and Surface Plasmon Research
- Spectroscopy and Quantum Chemical Studies
- Analytical chemistry methods development
- Quantum Dots Synthesis And Properties
- Advanced Polymer Synthesis and Characterization
- Tribology and Wear Analysis
- Metal and Thin Film Mechanics
- Atmospheric and Environmental Gas Dynamics
- Photosynthetic Processes and Mechanisms
- Integrated Circuits and Semiconductor Failure Analysis
- Optical Coatings and Gratings
- Marine Biology and Environmental Chemistry
- Photoreceptor and optogenetics research
- Photonic Crystals and Applications
University of Sheffield
2014-2025
LI-COR Biosciences (United States)
2025
Brooke
2016
Agency for Science, Technology and Research
2015
Institute of Materials Research and Engineering
2015
Tiger Optics (United States)
2012
Intertek (United Kingdom)
2010
Unilever (United Kingdom)
2010
University of Manchester
1999-2009
Montanuniversität Leoben
2008
A poly(glycerol monomethacrylate) (PGMA) macromolecular chain transfer agent has been utilized to polymerize benzyl methacrylate (BzMA) via reversible addition–fragmentation (RAFT)-mediated aqueous emulsion polymerization. This formulation leads the efficient formation of spherical diblock copolymer nanoparticles at up 50% solids. The degree polymerization (DP) core-forming PBzMA block systematically varied control mean particle diameter from 20 193 nm. Conversions more than 99% were...
A new cysteine-based methacrylic monomer (CysMA) was conveniently synthesized via selective thia-Michael addition of a commercially available methacrylate-acrylate precursor in aqueous solution without recourse to protecting group chemistry. Poly(cysteine methacrylate) (PCysMA) brushes were grown from the surface silicon wafers by atom-transfer radical polymerization. Brush thicknesses ca. 27 nm achieved within 270 min at 20 °C. Each CysMA residue comprises primary amine and carboxylic acid....
Abstract Computational protein design is advancing rapidly. Here we describe efficient routes starting from validated parallel and antiparallel peptide assemblies to two families of α-helical barrel proteins with central channels that bind small molecules. designs are seeded by the sequences structures defined de novo oligomeric barrel-forming peptides, adjacent helices connected loop building. For targets helices, short loops sufficient. However, require longer connectors; namely, an outer...
Abstract Protein adsorption and growth of primary human osteoblasts on self‐assembled monolayers alkylthiols gold (SAMs) with carboxylic acid hydroxyl methyl termini were investigated. Single‐component SAMs patterned by photolithographic techniques used. Cell demonstrated preferences for one pattern region in all combinations alkylthiols, the hierarchical preference COOH > OH CH 3 . Patterned immunochemistry used to investigate fibronectin albumin respect different alkylthiol termini....
Friction force measurements have been made using friction microscopy for a series of self-assembled monolayers (SAMs) alkanethiols varying chain lengths and terminal groups adsorbed on gold. The chemistry the tip was controlled by deposition SAM. When carboxylic acid terminated tips were employed, coefficients hydroxyl SAMs found to be greater than those methyl SAMs. However, although short-chain significantly long-chain SAMs, there not significant difference between values determined short-...
Molecular features with widths of only 20 nm have been fabricated in self-assembled monolayers alkanethiols on gold using a new lithographic tool, scanning near-field photolithography, based upon the use optical microscope (NSOM) coupled to UV laser. Quite unexpectedly it has proved possible routinely fabricate structures significantly smaller than aperture NSOM probe. This exceptional performance is strongly correlated morphology film. In particular, best results are achieved films...
The photooxidation of a range methyl terminated straight chain alkylthiol (CH3(CH2)n-1SH) self-assembled monolayers (SAMs) on Au has been investigated using X-ray photoelectron spectroscopy (XPS). process found to involve the oxidation thiolate group sulfonate by an active O2 species (possibly singlet oxygen). rate was vary strongly with alkyl length and correlated amount disorder within monolayers. Short-chain SAMs (n ≤ 8) have highest oxidize fastest, increasing sharply decreasing n, while...
Nanometer-scale patterns have been created in self-assembled monolayers by using a scanning near-field optical microscope coupled to an ultra-violet laser emitting light at wavelength of 244 nm. Sharp, chemically well-defined features with dimensions as small 40 nm routinely, and on occasions line widths 25 (λ/10) achieved. Because the wide range photochemical methods available for surface derivatization, this approach promises provide flexible versatile route generation molecular biological...
A quantitative investigation of the responses surface-grown biocompatible brushes poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC) to different types salt has been carried out using ellipsometry, quartz crystal microbalance (QCM) measurements, and friction force microscopy. Both cations anions varying valency over a wide range concentrations were examined. Ellipsometry shows that height is largely independent ionic strength, confirming degree swelling polymer character medium. In...
The frictional properties of poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC) brushes grown from planar silicon surfaces by atom transfer radical polymerization (ATRP) have been characterized using in situ friction force microscopy (FFM). dry thicknesses the PMPC ranged 20 to 421 nm. For brush layers with greater than ca. 100 nm, coefficient decreased increasing film thickness. shorter brushes, varied little We hypothesize that amount bound solvent increases as length increases,...
Gold nanostructure arrays exhibit surface plasmon resonances that split after attaching light harvesting complexes 1 and 2 (LH1 LH2) from purple bacteria. The splitting is attributed to strong coupling between the localized excitons in light-harvesting complexes. Wild-type mutant LH1 LH2 Rhodobacter sphaeroides containing different carotenoids yield energies, demonstrating mechanism sensitive electronic states Plasmon-exciton models reveal strengths depending on molecular organization...
Abstract Metal halide perovskite quantum dots (PQDs) have emerged as promising materials due to their exceptional photoluminescence (PL) properties. A wide range of applications could benefit from adjustable luminescence properties, while preserving the physical and chemical properties PQDs. Therefore, post‐synthesis engineering has gained attention recently, involving use ion‐exchange or external stimuli, such extreme pressure, magnetic electric fields. Nevertheless, these methods typically...
Primary human osteoblasts were cultured on self-assembled monolayers (SAMs) of alkylthiols gold with carboxylic acid and methyl termini, the kinetics cell attachment proliferation measured. Over 90 min approximately twice as many cells attached to carboxylic-acid-terminated methyl-terminated monolayers. After 24 h number was ten times that Cell morphology cytoskeletal actin organization also found be different. Osteoblasts SAMs patterned by photolithographic techniques. Cells almost...
Self-assembled monolayers (SAMs) of alkylthiols with polar terminal groups on gold may be photopatterned to produce structures that are stable against displacement by methyl-terminated thiols longer alkyl chains. For example, 3-mercaptopropanoic acid (MPA) patterns not eroded octadecanethiol (ODT). However, SAMs shorter than tetradecanethiol exposure solutions groups. dodecanethiol (DDT) MPA. The erosion process commences at boundaries between masked and unmasked regions the sample continues...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTOxidation of Self-Assembled Monolayers by UV Light with a Wavelength 254 nmNicholas J. Brewer, Rachel E. Rawsterne, Sherry Kothari, and Graham LeggettView Author Information Department Chemistry Materials Science Centre University Manchester Institute Technology PO Box 88, M60 1QD, UK Cite this: Am. Chem. Soc. 2001, 123, 17, 4089–4090Publication Date (Web):April 5, 2001Publication History Received4 January 2001Published online5 April inissue...
XPS and static SIMS have been employed to characterize the structures photooxidation of self-assembled monolayers (SAMs) alkylthiols on silver. Samples were prepared by immersing silver substrates in thiol solutions for a range times from 30 min 40 h, but no changes observed either compositions determined or spectra. Static spectra exhibited characteristic molecular species that facilitated quantification SAM structure following exposure UV light. Photooxidation led formation alkylsulfonate...
The rates of photooxidation self-assembled monolayers (SAMs) alkanethiols containing methyl, hydroxyl, and carboxylic acid terminal groups have been studied using static secondary ion mass spectrometry (SIMS). SIMS has revealed a wealth structure-specific peaks that enable the progress photochemical reactions within SAM to be monitored accurately effectively. addition eight methylene alkyl chain leads reduction in rate reaction by factor approximately 4. nature adsorbate group exerts...
The UV photo-oxidation of oligo(ethylene glycol) (OEG)-terminated self-assembled monolayers (SAMs) has been studied using static secondary ion mass spectrometry, X-ray photoelectron spectroscopy, contact angle measurement, and friction force microscopy. OEG-terminated SAMs are oxidized to yield sulfonates, but photodegradation the OEG chain also occurs on a more rapid time scale, yielding degradation products that remain bound surface via gold−sulfur bonds. oxidation these is rate-limiting...
Monolayers of alkylphosphonic acids (APA) and alkylcarboxylic (ACA) on magnetron-sputtered aluminum films have been investigated by friction force microscopy (FFM), contact angle measurement, polarization-modulation infrared reflection−absorption spectroscopy (PM-IRRAS). Clear evidence has provided from PM-IRRAS that coefficients, determined FFM data, may be correlated directly with variations in adsorbate molecular structure. The coefficient increased the length molecule, but reached a...