Electrochemical Donnan Effect Biosensors
Abstract
Our hypothesis is that antibodies, covalently bonded to inert membranes, will be charged, depending on the pH of the ambient electrolyte. A positive surface charge is a possible situation in low pH bathing solution. At low bathing concentrations of a pilot salt, such as sodium tetraphenylborate, sodium ions will be excluded from the membrane but anions will try to penetrate. To help the penetration we give the system a small driving force: unequal concentrations of pilot salt on the two sides. We expect a surface-charge- controlled membrane potential to arise initially. When antigen is added, a change in surface charge upon surface immunoreaction may cause an abrupt change in the membrane potential that we could use as an analytical signal. When there is no surface site charge, or when there is too high concentration of bathing electrolytes, there is a collapse of Donnan exclusion and salts simply diffuse through the membrane without regard for the surface charge barrier.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1990
- Accession Number
- ADA225241
Entities
People
- Richard P. Buck
Organizations
- University of North Carolina at Chapel Hill