Bead-based immunoassays employ the same basic principle as sandwich immunoassays. Capture beads, which can be differentiated by size and internal allophycocyanin (APC) fluorescence intensity, are conjugated to antibodies specific to a particular analyte. Next, a selected panel of defined capture bead sets is incubated with a biological sample containing target analytes specific to the capture a...

We have investigated the application of a modified, heterogeneous, competitive enzyme immunoassay for the continuous measurement of small analytes in a medium stream. The analytical system contains two antibodies that are immobilized on spatially separated areas, one binding the analyte (Ab1) and the other binding the enzyme (Ab2). An analyte-enzyme conjugate serves as signal generator. The ana...

Silver nanoparticles with a tuneable λ max were produced as colloids by heterogeneous nucleation. The synthesis process is both fast and repeatable, producing stable PVA capped nanoparticles. The colloid's effectiveness in the SERRS system was investigated using Rhodamine 6G, R6G, Crystal Violet, CV, and Malachite Green, MG, as probe molecules. A clear sensing trend was observed, where the Rama...

BACKGROUND Conceptionally, antibody microarrays are simply multiplexed sandwich immunoassays in a miniaturized format. However, from the amounts of capture antibodies used, it is not apparent whether such assays are ambient analyte (Ekins. Clin Chem 1998;44:2015-30) or mass-sensing devices (Silzel et al. Clin Chem 1998;44:2036-43). We evaluated multiplexed microarray sandwich assays for 24 mous...

Self-assembled phospholipid vesicles are functionalized with thrombin-binding aptamers using a thiol-click reaction. The resulting aptasensors signal the binding of the analyte to the vesicle surface by changes of the emission properties of membrane co-embedded reporter dyes.

A waveguide Mach-Zehnder Interferometer (MZI) immunosensor has been developed which can detect, in a direct way, a minimum average layer growth thickness of the analyte of 2X 10e3 nm (bound mass, I’=lX low4 fig cm-“). The design and fabrication of the sensor and the experimental set-up are aimed at decreasing the detection limit. A flow cell has been designed and incorporated into the set-up to...

Abstract Surface enhanced Raman spectroscopy is today an established technique used for chemical fingerprinting. Here, we showcase engineered hierarchical substrate, in which the plasmonically active regions, restricted to a micron scale, two dimensional hexagonal pattern are examined. Spatial variation of signal from any analyte, uniformly coating consequently bears high registry with underlyi...

Enzyme-based chemical biosensors are based on biological recognition. In order to operate, the enzymes must be available to catalyze a specific biochemical reaction and be stable under the normal operating conditions of the biosensor. Design of biosensors is based on knowledge about the target analyte, as well as the complexity of the matrix in which the analyte has to be quantified. This artic...