Shrink‐Induced Silica Structures for Far‐field Fluorescence Enhancements

Abstract

Dense multiscale silica (SiO 2 ) micro‐ and nanostructures are fabricated on a pre‐stressed polymer film. This novel SiO 2 substrate serves as a robust platform to enhance the fluorescence signal of bound biomolecules. Through a combination of surface concentration, light scattering, and changes in the photophysical properties of the confined dye molecules, dramatic fluorescence signal enhancements (average = 116 times greater than on planar glass) and increased signal‐to‐noise ratio (76:1) are demonstrated with tetramethylrhodamine isothiocyanate (TRITC)‐conjugated streptavidin (STRITC) on SiO 2 structures. Enhanced detection sensitivity of STRITC over glass on the SiO 2 structures is achieved down to a detection limit of 11 ng mL −1 . Such significant fluorescence signal enhancements have importance in practical applications such disease diagnostics and surface sensing.