Quantification of CEA from Human Plasma using Plasmonic Enhancement of Fluorescence and Acoustic Streaming

Abstract

Carcinoembryonic antigen (CEA) is a prognostic biomarker for colon cancer and is elevated in many other cancers such as ovarian cancer and pancreatic cancers. We introduce an optimized technique based on plasmonic enhancement of fluorescence to lower the detection limit of CEA to sub ng/ml levels. Nanostructures generated using rapid thermal annealing of thin silver films, covered by a silica layer, enhanced fluorescence intensity to lower the detection limit to about 100 pg/ml and increase sensitivity by a factor of 18. Additionally, acoustic streaming generated by Rayleigh surface acoustic waves (SAWs) was utilized to address interference from non-specifically bound (NSB) proteins in the quantification of CEA from human plasma. It is shown that NSB proteins in human plasma can be successfully reduced using acoustic streaming to achieve a CEA detection limit of 500pg/mL in plasma.