Learn More
In this study, we measured the frequency of revertants of a cytopathic strain of the duck hepatitis B virus that bears a single nucleotide substitution in the pre-S envelope protein open reading frame, resulting in the amino acid substitution G133E. Cytopathic virus mixed with known amounts of a genetically marked wild-type virus was injected into(More)
The spontaneous assembly of phospholipids at planar interfaces between thermotropic liquid crystals and aqueous phases gives rise to patterned orientations of the liquid crystals that reflect the spatial and temporal organization of the phospholipids. Strong and weak specific-binding events involving proteins at these interfaces drive the reorganization of(More)
The competitive binding of a molecule forming a liquid crystal and a targeted analyte to a common molecular receptor presented at a solid surface possessing nanometer-scale topography is used to trigger an easily visualized surface-driven change in the orientation of a micrometer-thick film of liquid crystal. Diffusion of the targeted analyte from(More)
We describe a simple optical method that employs measurement of the interaction energy of a liquid crystal (LC) with a surface (the so-called anchoring energy) to report proteins captured on surfaces through specific interactions with immobilized binding groups. To define the sensitivity and dynamic range of the response of the LC, we covalently immobilized(More)
Although much progress has been made in the identification and characterization of adhesins borne by pathogenic bacteria, the molecular details underlying their interaction with host receptors remain largely unknown owing to the lack of appropriate probing techniques. Here we report a method, based on atomic force microscopy (AFM) with tips bearing(More)
The ordering of liquid crystals (LCs) is known to be influenced by surfaces and contaminants. Here, we report that picogram per milliliter concentrations of endotoxin in water trigger ordering transitions in micrometer-size LC droplets. The ordering transitions, which occur at surface concentrations of endotoxin that are less than 10(-5) Langmuir, are not(More)
Protein microarrays are playing an increasingly important role in the discovery and characterization of protein-ligand interactions. The uniform orientation conferred by site-specific immobilization is a demonstrable advantage in using such microarrays. Here, we report on a general strategy for fabricating gold surfaces displaying a protein in a uniform(More)
Liquid crystals (LCs) were used to amplify and transduce receptor-mediated binding of proteins at surfaces into optical outputs. Spontaneously organized surfaces were designed so that protein molecules, upon binding to ligands hosted on these surfaces, triggered changes in the orientations of 1- to 20-micrometer-thick films of supported LCs, thus(More)
The combination of aqueous, alkaline cyanide ion (l M KOH, 0.1 M KCN) and dioxygen rapidly etches Au(0) (eq l).'-o Self-assembled monolayers (SAMs) of long-chain alkanethiolates 4Au * 8CN-+ 02 + 2H2O-4[Au(CN)z]-+ 4OH-(l) on the surface of the gold block this etching. Using a number of techniques-micromachining, microwriting, electron-beam lithography,(More)
Electrochemical control of the oxidation state of ferrocene-decorated electrodes leads to surface-driven changes in the orientations of thermotropic liquid crystals. When the electrodes possess nanometer-scale topography, voltages of 0.0 to 0.3 volts (versus a counter electrode in a two-electrode cell) can drive changes in the orientation of the liquid(More)