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Photolithographically generated patterns are created on immobilized CdSe QD thin films by fine-tuning their optical properties postsynthetically. The optically modified QDs have shown enhanced selectivity for binding of different ligand, which has helped in preparing optically reconfigurable surfaces for display and sensing applications.

The specific ion effects on interfacial water structure next to macromolecules were examined by using vibrational sum frequency spectroscopy (VSFS). The results indicate that the interfacial water structure could be responsible for the consequence of macromolecule-ion interactions.

Protein ion-channel recordings are described by using a glass nanopore (GNP) membrane as the support structure for lipid bilayer membranes. The electrical and mechanical stability of the bilayer and the ability to control ion-channel insertion have provided a new and nearly optimal system for single ion-channel recordings.

Multivalent ligand-receptor interactions are explored between pentameric cholera toxin B subunits (CTB) and the corresponding membrane ligand, ganglioside [GM.sub.1]. The results have shown that CTB binding to [GM.sub.1] is inhibited by the clustering of the glycolipid within the phospholipid membrane.

A method has been designed for patterning supported phospholipid bilayers (SLBs) on planar substrates and inside microfluidic channels. To do this, bovine serum albumin (BSA) monolayers were formed via adsorption at the liquid/solid interface. Next, this interfacial protein film was selectively patterned by using deep UV lithography. Subsequently, SLBs could be deposited in the patterned locations by vesicle fusion. By cycling through this process several times, spatially addressed bilayer arrays could be formed with intervening protein molecules serving as two-dimensional corrals. By employing this method, phospholipid bilayers containing various concentrations of ganglioside GM1 were addressed along the length of individual microfluidic channels. Therefore, the binding of GM1 with pentameric cholera toxin B (CTB) subunits could be probed. A seven-channel microfluidic device was fabricated for this purpose. Each channel was simultaneously patterned with four chemically distinct SLBs containing 0, 0.2, 0.5, and 2.0 mol % GM1, respectively. Varying concentrations of CTB were then introduced into each of the channels. With the use of total internal reflection fluorescence microscopy, it was possible to simultaneously abstract multiple equilibrium dissociation constants as a function of ligand density for the CTB-GM1 system in a single shot. [ABSTRACT FROM AUTHOR]

The present studies explore multivalent ligand-receptor interactions between pentameric cholera toxin B subunits (CTB) and the corresponding membrane ligand, ganglioside GM1. CTB binding was monitored on supported phospholipid bilayers coated on the walls and floors of microfluidic channels. Measurements were made by total internal reflection fluorescence microscopy (TIRFM). Apparent dissociation constants were extracted by fitting the binding data to both the Hill-Waud and Langmuir adsorption isotherm equations. Studies of the effect of ligand density on multivalent CTB-GM1 interactions revealed that binding weakened with increasing GM1 density from 0.02 mol % to 10.0 mol %. Such a result could be explained by the clustering of GM1 on the supported phospholipid membranes, which in turn inhibited the binding of CTB. Atomic force microscopy (AFM) experiments directly verified GM1 clustering within the supported POPC bilayers. [ABSTRACT FROM AUTHOR]

Investigates the ambivalent antibody binding on fluid-supported phospholipid membranes. Effect of hapten density on phospholipid membranes; Ligand-receptor binding between bivalent antibodies and membrane-boun ligands; Function of hapten density in a two-dimensionally fluid environment.

Examines the method of microfluidic measurement to generate a linear temperature gradient for parallel data and combinatorial measurements. Involvement of short length scales of microfluidics; Extension of method to protein crystallization; Additional variable of temperature in combinatorial tool box.

Investigates the design and characterization of immobilized enzymes in microfluidic systems. Possibility of rapid determination of enzyme kinetics by laminar flow controlled dilution; Mechanism of the enzyme immobilization on multiple chemical reactions; Employment of avidinD-conjugated glucose oxidase and streptavidin-conjugated horseradish peroxidase.

Describes a class of microfluidic immunoassays based upon solid supported lipid bilayers. Characteristics of the fluid bilayers used in the experiment; Method of deriving an entire binding curve in a single experiment; Advantages of the methodology for performing heterogeneous assays developed in the experiment over traditional procedures.

Reports on the use of microcontact displacement to generate addressable arrays of aqueous solutions above fluid lipid bilayers. Use of a patterned poly(dimethylsiloxane) mold; Conformal contact of the mold with a phospholipid membrane on a solid supported substrate; Use of the procedure for screening a small library of aqueous-phase molecules.

The article presents a study on lithosynthesis process using luminescent cadmium selenide (CdSe) quantum dots (QDs) thin film. It states that the ability of QD to create spatially addressable platforms with selective optical properties can be used to enhance various applications such as optoelectronics. It illustrates the visible light illumination using CdSe QD thin films and the QDs reversible surface modification.