Open AccessLabel-free real-time detection of biotinylated bovine serum albumin using a low-cost optical cavity-based biosensor
Author(s) -
Donggee Rho,
Seung Hyun Kim
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.018982
Subject(s) - biosensor , biotinylation , bovine serum albumin , streptavidin , materials science , detection limit , optics , optoelectronics , chemistry , nanotechnology , chromatography , biotin , physics , biochemistry
We have developed a low-cost optical cavity-based biosensor with a differential detection method for point-of-care medical diagnostics. To experimentally demonstrate its label-free real-time biosensing capability, we performed the detection of biotinylated bovine serum albumin (BSA). Streptavidin is introduced into the optical cavity structure and immobilized on 3-aminopropyltriethoxysilane (APTES) coated surface. After rinsing out unbound streptavidin with DI water, biotinylated BSA without any labeling is introduced. A CMOS camera captures the transmitted light of two different wavelengths passing through the optical cavity sensing area in real-time. Then, the differential values are calculated to enhance the responsivity. We successfully demonstrated the label-free real-time detection of biotinylated BSA, and the measurement results matched well with the simulation results. The limit of detection of the optical cavity-based biosensor for the biotinylated BSA detection with the sensing area of 180 μm × 180 μm is estimated to be 2.82 pM, which could be reduced further for a smaller sensing area with the tradeoff of a longer sensing time.