Fig. 5: The surface sensing and monitoring and the portable device designed for this thickness-modulated refractive index sensor.
From: Ultrasensitive imaging-based sensor unlocked by differential guided-mode resonance
a The monitoring response curve of the biotin molecule binding event (the concentration is 1 nmol/L). The insert is the surface modification process. APTES means 3-aminopropyltriethoxysilane. GA means glutaraldehyde. SA means streptavidin. BSA means bovine serum albumin. b The portable device design and its application. (i) A portable prototype (20 × 14 × 8 cm3) based on a plug-and-play sensor chip. (ii) Different ring-stripe images under various solution conditions. c (i) Two-dimension humidity (RH(r, θ)) sensing based on this thickness-modulated chip. (ii) The ring-stripe images as the humidity increases in a chamber, captured by the smartphone camera.
