Aligned silver nanowires for plasmonically-enhanced fluorescence detection of photoactive proteins in wet and dry environment

Abstract

We developed a method of aligning silver nanowires in a microchannel and fixing them to glass substrates via appropriate functionalization. The attachment of nanowires to the substrate is robust with no variation of their angles over minutes. Specific conjugation with photoactive proteins is observed using wide-field fluorescence imaging in real-time for highly concentrated protein solution, both in a microchannel and in a chip geometry. In the latter case we can detect the presence of the proteins in the dropcasted solution down to single proteins. The results point towards possible implementation of aligned silver nanowires as geometrically defined plasmonic fluorescence sensing platforms.

Keywords: Alignment; Fluorescence; Microchannel; Plasmon enhancement; Real-time detection; Silver nanowires.