We report the direct covalent functionalization of silicon and diamond surfaces with short ethylene glycol (EG) oligomers via photochemical reaction hydrogen-terminated terminal vinyl groups oligomers, use these monolayers to control protein binding at surfaces. Photochemical modification Si(111) polycrystalline produces EG linked Si-C bond formation (silicon) or C-C (diamond). X-ray photoelectron spectroscopy was used characterize monolayer composition. Measurements using fluorescently...

Carbon is an extremely versatile family of materials with a wide range mechanical, optical, and mechanical properties, but many similarities in surface chemistry. As one the most chemically stable known, carbon provides outstanding platform for development highly tunable molecular biomolecular interfaces. Photochemical grafting alkenes has emerged as attractive method functionalizing surfaces diamond, aspects chemistry impact on biological recognition processes remain unexplored. Here we...

In order to improve specific capacitance and limit electrical resistance, high-quality exfoliated graphene decorated with transition metal (Fe, Mn, Co) oxide nanoparticles (NPs) has been successfully synthesized without the use of surfactantvia a simple, general, environmentally-friendly chemical process. The as-prepared graphene/Mn3O4 composite reach 239.6 F/g, when employed as anode material in neutral NaCl electrolyte solutions (cf. 98.2 F/g for pristine 141.4 pure Mn3O4 NPs), which...

We used atomic force microscopy (AFM) to explore the antigen binding forces of individual Fv fragments antilysozyme antibodies (Fv). To detect single molecular recognition events, genetically engineered histidine-tagged were coupled onto AFM tips modified with mixed self-assembled monolayers (SAMs) nitrilotriacetic acid- and tri(ethylene glycol)-terminated alkanethiols while lysozyme (Lyso) was covalently immobilized SAMs carboxyl- hydroxyl-terminated alkanethiols. The quality...

The interaction of proteins with semiconductors such as silicon and diamond is great interest for applications electronic biosensing. We have investigated the use covalently bound oligo(ethylene glycol), EG, monolayers on to minimize nonspecific protein adsorption. Protein adsorption was monitored by fluorescence scanning a function length ethylene glycol chain (EG3 through EG6) terminal functional group (methyl- versus hydroxyl-terminated EG3 monolayer). More quantitative measurements were...

We report a study of the orientations nematic liquid crystals (LCs) in contact with peptide-modified, oligoethylene glycol-containing, self-assembled monolayers (SAMs). The SAMs were formed on gold films that prepared by physical vapor deposition at an oblique angle incidence. Two peptides investigated: optimized substrate for Src protein kinase (IYGEFKKKC) and synthetic equivalent peptide after modification (IpYGEFKKKC). Polarization modulation-infrared reflectance absorbance spectroscopy...

We compare two different strategies for covalently modifying carbon nanofibers with biological molecules such as DNA. One method begins a photochemical reaction between the and bearing both terminal olefin group protected amine followed by deprotection to yield free primary amine. The second uses chemical of an aryldiazonium salt electrochemical reduction Both methods then link amines thio-terminated DNA oligonucleotides. Our measurements show that DNA-modified exhibiting excellent...

Abstract A novel conductive anionic hydrogel was synthesized for use as a solid electrolyte electrochemical impedance spectroscopy (EIS) characterization of the barrier properties protective coatings on outdoor metalworks, such bronze sculptures. The AMPS‐co‐PAA soaked in variety aqueous salt solutions and characterized by swelling capacity conductivity order to determine most appropriate gel/liquid combination culturally significant objects. K 2 PIPES‐equilibrated hydrogels were selected...

We report the formation of continuous spatial gradients in density grafted semifluorinated chains on silicon oxide surfaces by vapor-phase diffusion silanes. quantify orientations nematic liquid crystal (LC) 4-cyano-4'-pentylbiphenyl these as a function local surface composition obtained using NEXAFS. These measurements demonstrate that it is possible to obtain full range tilt angles LC surfaces. also use data provided gradient test hypotheses regarding nature interaction between and give...

Changes in chemical, microstructural, and barrier properties of two commonly used commercially available waxes – a microcrystalline wax (Renaissance wax) carnauba blended (Butcher's Boston Polish Amber Paste Wax) for the prevention corrosion on outdoor metalwork were investigated. The applied to both plain patinated substrates bronze steel, films measured before after weathering. Accelerated weathering was performed by accelerated UV-B illumination/condensation under standard South Florida...

We report measurements of the orientations and azimuthal anchoring energies nematic liquid crystal 4-cyano-4'-pentylbiphenyl (5CB) on polycrystalline gold films that are deposited from a vapor at an oblique angle incidence subsequently decorated with organized monolayers oligomers ethylene glycol. Whereas covered presenting tetra(ethylene glycol) (EG4) lead to 5CB perpendicular plane gold, tri(ethylene (EG3) direct orient parallel during deposition film. also measure energy be smaller...

Abstract Electrical properties of thin dielectric films at the solid‐liquid phase boundary are an important performance characteristic many devices, coatings and sensors. In this paper, co‐polymeric hydrogels polyacrylic acid co‐sulfonic acid, swollen with a salt solution to act as solid electrolyte, were used assess interfaces using electrochemical impedance spectroscopy (EIS) in co‐planar geometry. Silane‐modified glasses characterized by hydrogel EIS cell found be distinguishable based on...

We have investigated the formation and electrical properties of nanowire bridges formed when nanowires modified with biomolecule biotin span across a gap between gold microelectrodes functionalized complementary biomolecule, avidin. Dielectrophoretic manipulation 1 MHz AC voltage is used to manipulate biotin-modified into inter-electrode gap. Biomolecular recognition avidin-modified then holds securely in place. By simultaneously applying second, lower-frequency using lock-in detection, we...

We report a methodology that permits quantitation of the azimuthal anchoring energy nematic liquid crystal 4-cyano-4'-pentyl-biphenyl on surfaces patterned with oligopeptides. The oligopeptide (IYGEFKKKC), an optimized substrate for Src protein kinase, was covalently immobilized via terminal cysteine to monolayers amine-terminated tetra(ethylene glycol) formed gold films. measurements energies, which were based torque-balance method, revealed systematic decrease in from 3.7 ± 0.6 μJ/m2...

Nanoclays are small enough to appear optically transparent, yet they have large surface-to-volume and high aspect ratios that can significantly inhibit water diffusion when incorporated into protective coatings. Clear coatings, which minimally affect the aesthetics of metalworks, commonly applied outdoor such as sculptures, prevent slow corrosion. In recent years, waterborne clear rather than solvent-based increasingly used in many applications reduce quantity volatile organic components...

In this work, we used chemically cross-linked acrylamide-based hydrogel patches that have been specifically developed for use as solid electrolytes in Electrochemical Impedance Spectroscopy to measure the impedance of two waxed bronze sculptures at Seattle Art Museum’s (SAM) Olympic Sculpture Park (OSP) and compare those results laboratory test panels. We determined response frequency range which measurements may be taken (10 kHz 1 MHz) is mostly capacitive a freshly applied wax coating...

Abstract Defective polymeric coatings that are particularly relevant in the conservation of outdoor metalwork, analyzed using electrochemical impedance spectroscopy (EIS), validated by KramersKronig transformations, and modeled electrical equivalent circuit models (EECs). Using twenty different coated panels five coating types, ten mathematical methods for categorizing protective qualities explored as simpler faster alternatives to modeling; three gave a perfect correlation with category...

Fluorescence spectroscopy experiments are a frequently taught as part of upper-division teaching laboratories. To expose undergraduate students to an applied fluorescence technique, corrosion detection method, using quenching, was adapted from authentic research for instrumental analysis laboratory. In the experiment, acquire spectra sensing molecules in presence mock sculpture samples and discuss condition sculptures based on levels soluble iron detected. This real-world-based experiment...

Abstract Red organic dye identification is an important topic for conservation of Japanese ukiyo-e prints. Of particular interest are the works Suzuki Harunobu, who was working at inception full-color printmaking. These prints were made on thin kōzo paper and woodblock printed with semi-transparent to opaque regions dye(s) and/or pigment(s) mixed binder. This study used imaging analysis, X-ray fluorescence (XRF), Raman, surface-enhanced Raman spectroscopies (SERS) identify red dyes pigments...