Analytical Sciences

Abstract − Analytical Sciences, 28(10), 947 (2012).

Highly Sensitive Fluorescence Detection of Avidin/Streptavidin with an Optical Interference Mirror Slide
Mitsuru YASUDA and Takuo AKIMOTO
School of Bioscience and Biotechnology, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo 192-0982, Japan
This paper presents highly sensitive fluorescence detections of avidin and streptavidin using an optical interference mirror (OIM) slide consisting of a plane mirror covered with an optical interference layer. Compared with a common glass slide, the OIM slide can enhance the fluorescence from a dye by more than 100-fold. We fabricated an OIM slide by depositing an optical interference layer of Al2O3 on an Ag mirror. To enhance the fluorescence maximally, the optimal thickness of the Al2O3 layer was estimated from optical interference theory. For detections of protein, avidin/streptavidin labeled with fluorescein, Cy3, and Cy5 were detected with biotin immobilized on an OIM slide with the optimal Al2O3 thickness. We achieved a sensitivity improvement of more than 50-fold, comparing with a glass slide. Such a high degree of improvement would be a significant contribution to further progress in biomedical research and medical diagnostics.