Integrated Tunable Laser Cavity Sensor for Immunoassay Analysis and Molecular Diagnostics

摘要

The current research is focused in two major areas: integrated laser design & development and microfluidic channel design with ac electrokinetic transport. We have modified the integrated laser design to make the waveguide symmetric. This allows for greater coupling between the laser sensor and the assay, and improves sensitivity by two orders of magnitude. The integrated sensor could measure up to 100 femtogram resolution. By tagging a latex bead to the analyte, the sensor can approach single molecule sensitivities. AC electrokinetically- driven microscale fluid and particle motion have been investigated for microfluidic design. We have focused on two mechanisms of sensor enhancent AC fields can produce fluid circulation, for example through electrothermal forces, to enhance analyte motion towards ligands immobilized on the laser sensors. Additionally, AC fields can preduce forces on particles directly, through dielectrophoresis (DEP), for concentration of analyte near the sensor. These two phenomena are investigated using numerical simulations. The results indicate that sensitivity and response time can be improved by nearly an order of magnitude for diffusion-limited reactions. This work is continuing with support from ARO through the Institute for Intercollaborative Biotechnology (ICB). We are also working with Dr. Nick Fell's group at ARL in Adelphi, MD to transition the work to Army applications.