A colorimetric biosensing system based on a porous silicon (PSi) rugate filter is demonstrated. Using an imaged-based technique that monitors RGB intensity, a spectral shift less than 0.25nm can be reliably detected. The porous silicon rugate filter demonstrates a sensitivity of 310 nm/RIU, which corresponds to a detection limit near 7×10^-4 RIU. In this work, an external light source and camera are employed for proof-of-concept demonstration. By utilizing a smartphone camera LED and smartphone camera as the light source and detector, respectively, this system could serve as an effective, low-cost, point-of-care diagnostic tool.

Date Published: 22 February 2017
PDF: 7 pages
Proc. SPIE 10077, Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XIV, 1007713 (22 February 2017); doi: 10.1117/12.2250659

Published in SPIE Proceedings Vol. 10077:
Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XIV
Alexander N. Cartwright; Dan V. Nicolau; Dror Fixler, Editor(s)