Ultra-sensitive plasmonics sensors for refractive index.
(A) Top view and (B) tilted view of SEM images of nanoLCA plasmonic sensor. (C) Optical images of different concentrations of glycerol on nanoLCA (A–C adapted from Ref. ). (D) Optical transmission mode images of nanoLCA with 14 different chemicals with varying refractive indices. (E) Colorimetric variations due to different concentrations of target and probe DNA strands immobilized from nanoLCA sensor (D and E adapted from Ref. ). (F) SEM image of the surface of FlexBrite. (G) Photograph of a piece of FlexBrite sample. (H) Detection of antibody-antigen reaction (biotin-streptavidin binding) with plasmonic colorimetry of FlexBrite: the process of functionalization of thiolated biotin on the surface of FlexBrite and conjugation with streptavidin (top); colors of FlexBrite in the wet state with water, after functionalization with thiolated biotin and after binding of biotin with streptavidin (bottom) (F and G adapted from Ref.  with permission from The Royal Society of Chemistry).