Development and Evaluation of realistic Microbioassays in Droplets on a Chip
Abstract
We developed a novel technique for biomolecular detection in microliter droplets floating on the surface of high density oil. Each droplet was captured and manipulated dielectrophoretically and was used as a site for a microscopic bioassay based on agglutination of antibody-conjugated particles. The results were read out by the pattern of agglomerated gold nanoparticles collected on the droplet surface. Two formats of bioassays, namely GOAgg (Gold Only Agglutination) and GLAgg (Gold and Latex Agglutination), were investigated experimentally by varying analyte concentration, particle size and concentration, number of antigen binding sites per particle, time for incubation and rate of particle collection on the droplet surface. The microbioassays performance was also evaluated with Ricin antibodies and compared to the Army Ricin assays in field use. We estimate that the droplet based assays require 100 times smaller sample volume and are ten times more sensitive, though they require longer times to complete. The experiments were interpreted by modeling the kinetics of particle agglutination and mass transfer processes inside the droplets. The results could allow for development of efficient immunoassays on a chip requiring even smaller sample volumes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 27, 2007
- Accession Number
- ADA482942
Entities
People
- Orlin D. Velev
Organizations
- North Carolina State University