NANOSCALE: Miniaturized On-chip Biosensors by In Situ Assembly of Colloidal Particles

University Of Delaware, Newark DE

Investigators

Abstract

Miniaturized sensors will be created by interfacing of colloidal assemblies with on-chip micropatterned electrodes. The microscopic, electronically readable biosensors will be assembled in situ from latex particles. The active areas of the sensors will be generated from suspended particles collected in micrometer-sized gaps between the electrodes under the action of dielectophoesis and assembled by modification of the operating colloidal interactions. The key step in particle immobilization into sensor patches will be to decrease the repulsive interactions to a degree where the van der Waals and hydrophobic forces coagulate the particles. The theoretical limit of detection of the microscopic sensors approaches an extremely low limit of a few hundred molecules. One goal will be to study methods for improvements of devices previously fabricated. Speed and sensitivity will be increased by generating an electro-osmotic flux over the sensor area and by optimizing the gap geometry. Sensors based on direct protein immobilization in the gap between the electrodes fabricated by microstamping will also be developed. If successful, this work will lead to an improved sensor for rapid, sensitive immunological testing.