Dual-mode bioenabled nano-plasmonic sensors for biological and chemical detection

Plasmonic biosensors have greatly overcome the limitations of conventional optical sensors in terms of sensitivity, tunability, photo-stability, and in vivo applicability. In this paper, we present plasmonic biosensors using bioenabled nanomaterials diatom biosilica, with active surface functionalities as affordable and eco-friendly integration platforms of Ag nanoparticles for label-free detection of biomolecules. Dual-mode plasmon sensing mechanisms, including surface-enhanced Raman scattering (SERS) and refractive-index (RI) sensing will be simultaneously implemented on the plasmonic-biosilica nanostructures to obtain quantitative biosensing with structural resolution of the biomolecules. We have achieved ultra-sensitive detection of Rhodamine 6G (R6G) at concentrations as low as 10 −10 M. Furthermore, this substrate was used to detect TNT, illustrating the potential application as viable substrates for monitoring pollutant and toxics in environment.