Molecular interferometric imaging for biosensor applications
Abstract
Molecular interferometric imaging (MI2) is a common-path interferometric imaging technique for detecting protein binding to surfaces. The experimental metrology limit is 10 pm/pixel longitudinal resolution at 0.4-mu m diffraction-limited lateral resolution, corresponding to 1.7 attogram of protein, which is only 8 antibody molecules per pixel, near to single-molecule detection. The scaling mass sensitivity at the metrology limit is 5 fg/mm. We demonstrate a protein microarray application in a 128-multiplex immunoassay. Assay applications include prostate specific antigen (PSA) at a detection limit of 60 pg/mL and the cytokine interieukin-5 (IL-5) at a detection limit of 50 pg/mL. Real-time binding assays using MI2 enable the study of reaction kinetics of antibodies exposed to antigen, and the binding of antibody Fc regions to protein G.
Published in:
Ieee Journal of Selected Topics in Quantum Electronics 13,6 (2007) 1680-1690;
Link to original published article:
http://dx.doi.org/10.1109/JSTQE.2007.911002
Keywords
biomedical optics;; biosensor;; immunoassay;; interferometry;; label-free;; protein microarray;; Engineering, Electrical & Electronic;; Optics
Date of Version
1-1-2007
Recommended Citation
Zhao, M.; Wang, X. F.; Lawrence, G. M.; Espinoza, P.; and Nolte, D. D., "Molecular interferometric imaging for biosensor applications" (2007). Department of Physics and Astronomy Faculty Publications. Paper 681.
https://docs.lib.purdue.edu/physics_articles/681