Monday, June 18, 2007 - 10:30 AM
The Kestrels (Boise Centre on the Grove)

Nanomonitors: Electrical Immunoassay

Ravikiran K. Reddy and Shalini Prasad. Portland State University, Portland, OR

The best predictor of post operative outcome for cardio-vascular surgery is the presence of preoperative ischemia, which is caused by vulnerable coronary plaque rupture. The goal of this research project is the non-invasive identification of protein biomarkers for vulnerable coronary plaque rupture that results in poor post-surgical outcomes. In the perioperative state, this condition is characterized by inflammation and thrombosis. The heterogeneity of this disease makes early detection inconclusive based on the identification of a single protein biomarker. The traditional assay detection technique for this disease state is limited by single protein biomarker detection, complexity, and turnaround time. Our technique addresses these gaps in the current technology. We have created a nanowell detection methodology by scaling down the size of the microwells to nanowells, using pl volumes and improving the sensitivity by adopting the tested biochemical approach. The most significant advantage is the ability to detect multiple disease markers using one single device.We have demonstrated the effectiveness of nanoporous alumina based electrical biosensors in identification of two biomarkers, associated with this disease-C-Reactive Protein and Myeloperoxidase. We have succesfully demonstrated a label free technique with improved speed of detection, with reagent minimization and comparable sensitivity to the Enzyme Linked Immunosorbent Assay (ELISA) with multiplexed detection capability. The principle of operation of these biosensors is based on the detection of the change in the electro chemical signal at the electrode, based on the modulation of the electric double layer at the interface of the electrode and the binding site, associated with the formation of the antibody-antigen binding complex. Using this approach we have achieved detection sensitivity of upto 1ng/ml.