Rapid and Simple Immunoassay Based on Negative Dielectrophoresis with Three-Dimensional Interdigitated Array Electrodes

Abstract

Rapid accumulations of particles and living cells with negative dielectrophoresis (n-DEP) have been applied to develop the rapid and simple immunosensing method. Grid formation of electrodes was fabricated by rotating the upper template interdigitated microband array (IDA) electrode by 90º relative to the lower IDA. When AC electric signal was applied to the bands on the upper and lower IDA, island organization was rapidly formed at the intersections with low electric fields. The accumulated particles were fixed through the immunoreactions between the antibody immobilized on the particle surface and analytes in the solution. The presence of the specific antigens allowed the formation of fixed complexes of particles. It is noted that the time required for single sensing is as short as 5 min and separation steps are eliminated in the presented procedure. We demonstrated the rapid and simple immunosensing using the aggregation of particles accumulated with DEP.