Replication Data for: Large area silver-stibnite nanoporous plasmonic films for label-free biosensing

The development of various plasmonic nanoporous materials have attracted much interest in different areas of research including bioengineering and biosensing because of their large surface area and versatile porous structure. Here, we introduce a novel technique for fabricating silver-stibnite nanoporous plasmonic films. Unlike conventional techniques that are usually used to fabricate nanoporous plasmonic films, we use a room temperature growth method that is wet-chemistry free, which enables wafer-scale fabrication of nanoporous films on flexible substrates. We show the existence of propagating surface plasmon polaritons in nanoporous films, and demonstrate the extreme bulk refractive index sensitivity of the films using Goos-Hänchen shift interrogation scheme. In the proof-of-concept biosensing experiments, we functionalize the nanoporous films with biotin-thiol using a modified functionalization technique, in order to capture streptavidin. The fractal nature of the films increases the overlap between the local field and the immobilized biomolecules. The extreme sensitivity of the Goos-Hänchen shift allows femtomolar concentrations of streptavidin to be detected in real-time, which is unprecedented using surface plasmons excited via the Kretschmann configuration.