A5070876073- Mass Spectrometry Techniques and Applications
- Advanced Proteomics Techniques and Applications
- Ion-surface interactions and analysis
- Analytical Chemistry and Chromatography
- Analytical chemistry methods development
- Gold and Silver Nanoparticles Synthesis and Applications
- Metabolomics and Mass Spectrometry Studies
- Chemical Synthesis and Analysis
- Alzheimer's disease research and treatments
- Advanced biosensing and bioanalysis techniques
- Nanoparticle-Based Drug Delivery
- Trace Elements in Health
- Biotin and Related Studies
- Protein Structure and Dynamics
- Electrochemical Analysis and Applications
- Supramolecular Self-Assembly in Materials
- Monoclonal and Polyclonal Antibodies Research
- Metal complexes synthesis and properties
- Nanoparticles: synthesis and applications
- Nanocluster Synthesis and Applications
- Click Chemistry and Applications
- Biosensors and Analytical Detection
- Microfluidic and Capillary Electrophoresis Applications
- Advanced Nanomaterials in Catalysis
- Crystallization and Solubility Studies
University of Massachusetts Amherst
2016-2025
Amherst College
2016-2022
Bruker (United States)
2008
East Carolina University
2008
University of North Carolina at Chapel Hill
1995-2005
University of Kansas
2005
United States Naval Research Laboratory
1998-2003
Naval Research Laboratory Chemistry Division
2003
National Academies of Sciences, Engineering, and Medicine
1999-2000
Oak Ridge National Laboratory
1998
The mean size of the gold (Au) core in synthesis dodecanethiolate-stabilized Au cluster compounds can be finely adjusted by choice Au:dodecanethiolate ratio and temperature rate at which reduction is conducted. clusters have been examined with a large number independent analytical tools, producing remarkably consistent picture these materials. Average dimensions, as ascertained 1H NMR line broadening, high-resolution transmission electron microscopy, small-angle X-ray scattering,...
Small (6-10 nm) functionalized gold nanoparticles (AuNPs) featuring different, well-defined surface charges were used to probe the uptake and distribution of nanomaterials in terrestrial plants, including rice, radish, pumpkin, perennial ryegrass. Exposure AuNPs plant seedlings under hydroponic conditions for a 5-day period was investigated. Results from these studies indicate that AuNP depend on both nanoparticle charge species. The experiments show positively charged are most readily taken...
Surface chemistry plays a deciding role in nanoparticle biodistribution, yet very little is known about how surface influences the suborgan distributions of nanomaterials. Here, using quantitative imaging based on laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), we demonstrate that charge dictates nanoparticles kidney, liver, and spleen mice intravenously injected with functionalized gold nanoparticles. Images kidney show positively charged accumulate extensively...
Occupational and environmental exposure to Co Cr has been previously linked a wide array of inflammatory degenerative conditions cancer. Recently, significant health concerns have raised by the high levels ions corrosion products released biomedical implants. Herein, we set analyze biological responses associated with toxicity. Histological, ultrastructural elemental analysis, performed on exposed patients reveal presence products, metallic wear debris metal at varying concentrations....
The effects of Al2O3, TiO2, and ZnO nanoparticles (NPs) on bacteria cells bacterial surface biomolecules were studied by Fourier transform infrared (FTIR) spectroscopy. All the examined showed IR spectral changes after NP exposure. Lipopolysaccharide lipoteichoic acid could bind to oxide NPs through hydrogen bonding ligand exchange, but cytotoxicity seemed largely related function-involved or devastating proteins phospholipids bacteria. three decreased intensity ratio β-sheets/α-helices,...
Monolayer-protected gold nanoparticles (AuNPs) were used to demonstrate how surface chemistry influences the uptake, distribution, and excretion of nanomaterials in Japanese medaka fish. Hydrophilic AuNPs found primarily fish intestines, showing no obvious health effects on Hydrophobic cationic has a broad distribution organs lead ultimately mortality < 24 h. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not...
Bioorthogonal activation of prodrugs provides a strategy for on-demand on-site production therapeutics. Intracellular to localize therapeutics, potentially minimizing off-target effects. To this end, nanoparticles embedded with transition metal catalysts (nanozymes) were engineered generate either "hard" irreversible or "soft" reversible coronas in serum. The hard corona induced nanozyme aggregation, effectively inhibiting activity, whereas only modest loss activity was observed the...
Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) has been used to generate spatial maps of lipids, metabolites, peptides, proteins, and glycans in tissues; however, its use for mapping extracellular matrix (ECM) protein distributions is underexplored. ECM proteins play a major role various pathological conditions, changes their affect the function morphology cells within tissues. detection challenging because they are large, insoluble, undergo...
Gold nanoparticles (AuNPs) are highly promising candidates as drug delivery agents into cells of interest. We describe for the first time multiplexed analysis nanoparticle uptake by using mass spectrometry. demonstrate that cellular functionalized gold with cationic or neutral surface ligands can be readily determined laser desorption/ionization spectrometry cell lysates. The have "mass barcodes" allow different to simultaneously identified and quantified at levels low 30 pmol. Using this...
The antioxidant activities of aqueous phase β-lactoglobulin (β-Lg) and its chymotryptic hydrolysates (CTH) were compared in this study. Proteins peptides have been shown to inhibit lipid oxidation reactions oil-in-water emulsions; however, a more fundamental understanding the activity these compounds dispersed food systems is lacking. CTH was effective than an equivalent concentration β-Lg retarding when continuous Brij-stabilized emulsions (pH 7). Furthermore, it observed that had higher...
The reliability and information content of diethylpyrocarbonate (DEPC) as a covalent probe protein surface structure has been improved when used appropriately with mass spectrometric detection. Using myoglobin, cytochrome c, β-2-microglobulin model systems, we demonstrate for the first time that DEPC can modify Ser Thr residues in addition to His Tyr residues. This result expands capability structural because about 25% sequence average now be covered using this labeling reagent. In addition,...
Imaging of nanomaterials in biological tissues provides vital information for the development nanotherapeutics and diagnostics. Multiplexed imaging different nanoparticles (NPs) greatly reduces costs, need to use multiple animals, increases biodistribution that can enhance diagnostic applications accelerate screening potential therapeutics. Various approaches have been developed NPs; however, readout existing techniques relies on specific properties core material or surface ligands, these...
A critical factor for controlling serum albumin binding is surface hydrophobicity, which in turn decreases the cellular uptake of gold nanoparticles. Hydrophobic nanoparticles bind more tightly, inhibiting particle uptake, with a direct correlation observed between and hydrophobicity.
Unique intramolecular rearrangement product ions have been observed in the ion spectra of a number peptides. Multiple stages mass analysis (MSn), molecular modeling, and chemical modifications peptides used to provide insight into mechanism this reaction. The process begins with four-residue immonium that transfers proton from nitrogen primary amine on N-terminus. transfer leads peptide, exposing an internal amino acid terminus new ion. becomes is then readily lost. reaction seems benefit...
β-2-Microglobulin (β2m) self-associates into fibrillar amyloid deposits in the musculoskeletal system of patients undergoing hemodialysis treatment. Previous studies have shown that stoichiometric amounts Cu(II) at near physiological conditions can cause β2m to organize native-like dimers prior forming fibrils. Here, we report results from selective covalent labeling reactions combined with mass spectrometry provide insight amino acid residues mediate dimer formation wild-type protein. Using...
The gas-phase structures of protein ions have been studied by electron transfer dissociation (ETD) and collision-induced (CID) after electrospraying these proteins from native-like solutions into a quadrupole ion trap mass spectrometer. Because ETD can break covalent bonds while minimally disrupting noncovalent interactions, we investigated the ability this technique together with CID to probe sites electrostatic interactions in ions. By comparing spectra followed CID, find that several...
Covalent labeling with mass spectrometry is increasingly being used for the structural analysis of proteins. Diethylpyrocarbonate (DEPC) a simple to use, commercially available covalent reagent that can readily react range nucleophilic residues in We find intact proteins weakly side chains (Ser, Thr, and Tyr) be modified by DEPC addition other such as His, Lys, Cys, providing very good resolution. hypothesize microenvironment around these chains, formed protein's higher order structure,...