Open AccessPerformance limitations of resonant refractive index sensors with low-cost components
Author(s) -
Alexander Drayton,
Kezheng Li,
M. Y. Simmons,
Christopher Reardon,
Thomas F. Krauss
Publication year - 2020
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.400236
Subject(s) - refractive index , sensitivity (control systems) , computer science , optics , noise (video) , cmos sensor , detector , fault detection and isolation , biosensor , laser , diode , image sensor , electronic engineering , materials science , optoelectronics , physics , artificial intelligence , nanotechnology , engineering , actuator , image (mathematics)
Resonant biosensors are attractive for diagnostics because they can detect clinically relevant biomarkers with high sensitivity and in a label-free fashion. Most of the current solutions determine their detection limits in a highly stabilised laboratory environment, which does, however, not apply to real point-of-care applications. Here, we consider the more realistic scenario of low-cost components and an unstabilised environment and consider the related design implications. We find that sensors with lower quality-factor resonances are more fault tolerant, that a filtered LED lightsource is advantageous compared to a diode laser, and that a CMOS camera is preferable to a CCD camera for detection. We exemplify these findings with a guided mode resonance sensor and experimentally determine a limit of detection of 5.8 ± 1.7×10 -5 refractive index units (RIU), which is backed up by a model identifying the various noise sources. Our findings will inform the design of high performance, low cost biosensors capable of operating in a real-world environment.