11-mercaptoundecanol and 11-mercaptoundecanoic-acid

Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, as a technique, offers detailed information about the bonding environment of molecules at a surface. However, because it is a synchrotron based method, beam-time is limited and users must typically prioritize and narrowly define the scopes of experiments. In this study, we demonstrate a novel method that opens up the possibility of the use of large area NEXAFS imaging to pursue combinatorial studies. To explore the capabilities of the NIST full field NEXAFS microscope available at the National Synchrotron Light Source as a high throughput imaging instrument, we collected NEXAFS images from a sample array consisting of 144 different elements with a periodic sequence of different surface modifications. NEXAFS images collected from this model system illustrate how hyperspectral NEXAFS data can be used for parallel analysis of large numbers of samples either directly from the overall image or by extracting spectra from regions of interest.

Topics: Fatty Acids; Fatty Alcohols; Molecular Structure; Sulfhydryl Compounds; Surface Properties; X-Ray Absorption Spectroscopy

Polylactic-co-glycolic acid (PLGA) based nanoparticles are biocompatible and biodegradable and therefore have been extensively investigated as therapeutic carriers. Here, we engineered diagnostically active PLGA nanoparticles that incorporate high payloads of nanocrystals into their core for tunable bioimaging features. We accomplished this through esterification reactions of PLGA to generate polymers modified with nanocrystals. The PLGA nanoparticles formed from modified PLGA polymers that were functionalized with either gold nanocrystals or quantum dots exhibited favorable features for computed tomography and optical imaging, respectively.

Topics: Diagnostic Imaging; Fatty Acids; Fatty Alcohols; Gold; Metal Nanoparticles; Microscopy, Electron, Transmission; Polyglycolic Acid; Quantum Dots; Sulfhydryl Compounds

Unfolding turns immobilized cytochrome c into a His-His ligated form endowed with catalytic activity towards O(2), which is absent in the native protein. Dioxygen could be used by naturally occurring unfolded cytochrome c as a substrate for the production of partially reduced oxygen species (PROS) contributing to the cell oxidative stress.

Topics: Biocatalysis; Cytochromes c; Electrochemistry; Electrodes; Enzymes, Immobilized; Fatty Acids; Fatty Alcohols; Gold; Hydrophobic and Hydrophilic Interactions; Oxidation-Reduction; Oxygen; Protein Unfolding; Sulfhydryl Compounds

Topics: Absorption; Fatty Acids; Fatty Alcohols; Metal Nanoparticles; Static Electricity; Sulfhydryl Compounds; Surface Plasmon Resonance; Surface Properties; Thermodynamics; Unilamellar Liposomes

Silver electrodes were covered with mixed self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) and 11-mercaptoundecanol (MU) and subsequently coated with alternating layers of cytochrome c (Cyt) and poly(anilinesulfonic acid) (PASA). The immobilized protein is electroactive and retains its native structure. Compared to the case of systems on gold electrodes, the stability of the assembly was found to be decreased. The redox process of Cyt is accompanied by reversible oxidation-reduction of PASA as revealed by the comparative surface-enhanced resonance Raman (SERR) analysis of assemblies including Cyt and the redox-inactive apo-cytochrome c. Time-resolved SERR experiments show a fast electron exchange between the protein and the polyelectrolyte that may play a supporting role in the electric communication of thicker multilayer assemblies employed as sensors.

Topics: Aniline Compounds; Animals; Biosensing Techniques; Coated Materials, Biocompatible; Cytochromes c; Electrodes; Electrolytes; Electron Transport; Fatty Acids; Fatty Alcohols; Gold; Oxidation-Reduction; Silver; Spectrum Analysis, Raman; Sulfhydryl Compounds; Surface Properties