Absorbance amplification on nanocup array structure (nanoLCA).
(A) SEM image of the nanocup array structure in top-down view and in a cross-section view. (B) Absorbance spectra of the nanocup array structure in air and in water. (C) Schematic representation of energy diagram to show energy transfer mechanism between plasmon and dye molecule. (D) Relative absorbance changes with increasing BSA concentration with and without the nanocup array structure (A–D reprinted with permission from ; copyright (2015) American Chemical Society).