Crossed Surface Relief Gratings as Nanoplasmonic Biosensors

• DOI: 10.1021/acssensors.6b00696
• Publication Date: 2017-02-17T11:37:42Z
• Authors: Srijit Nair; Carlos Escobedo; Ribal Georges Sabat
• Keywords: Figure of Merit; Streptavidin; Molecular binding

We present an original, low-cost nanoplasmonic (bio)sensor based on crossed surface relief gratings (CSRGs) generated from orthogonally superimposed (SRGs) gold-coated azo-glass substrate. This plasmon resonance (SPR)-based sensing approach is unique, since the light transmitted through a CSRG zero except in narrow bandwidth where SPR conversion occurs, enabling quantitative monitoring of only plasmonic signal biomolecular interactions real time. validated individual SRG signature CSRGs by observing their respective excitation peaks, and tested them to detect both bulk near-surface refractive index (RI) changes. Compared simple SRGs, portray much-improved sensitivity 647.8 nm/RIU, resolution order 10-5 RIU, figure merit (FOM) 14 for RI-change sensing. also demonstrate ability perform as biosensors, detection time, first CSRGs. The minimum detectable concentration biotin-streptavidin binding events was 8.3 nM. Due abilities, low cost (<10 cents/unit), ease fabrication, inherent suitability integration with microfluidics, we anticipate that will stand strong candidates portable diagnostics arena.