A Highly Tunable and Fully Biocompatible Silk Nanoplasmonic Optical Sensor

Abstract

Novel concepts for manipulating plasmonic resonances and the biocompatibility of plasmonic devices offer great potential in versatile applications involving real-time and in vivo monitoring of analytes with high sensitivity in biomedical and biological research. Here we report a biocompatible and highly tunable plasmonic bio/chemical sensor consisting of a natural silk protein and a gold nanostructure. Our silk plasmonic absorber sensor (SPAS) takes advantage of the strong local field enhancement in the metal-insulator-metal resonator in which silk protein is used as an insulating spacer and substrate. The silk insulating spacer has hydrogel properties and therefore exhibits a controllable swelling when exposed to water-alcohol mixtures. We experimentally and numerically show that drastic spectral shifts in reflectance minima arise from the changing physical volume and refractive index of the silk spacer during swelling. Furthermore, we apply this SPAS device as a glucose sensor with a very high sensitivity of 1200 nm/RIU (refractive index units) and high relative intensity change.

Theoretical design of a surface plasmon resonance sensor with high sensitivity and high resolution based on graphene–WS2 hybrid nanostructures and Au–Ag bimetallic film

“…However, for angle interrogation, only monochromatic light is required, it is possible to achieve higher signal-to-noise ratio due to the wavelength and power stability of the source. [5][6][7][8][9][10][11] Thus, angle interrogation is adopted in this article.…”

A high-performance and low cost SERS substrate of plasmonic nanopillars on plastic film fabricated by nanoimprint lithography with AAO template

“…7 Specifically, it has been greatly demonstrated that the metallic nanostructures with strongly enhanced local electric field bears the advantages of being non-destructive, highly-sensitive and label-free bio-sensor. [8][9][10] Of particular interest is the combination of metallic nanostrucrures and Raman spectroscopy that would provide a powerful analytical technique, namely, surface-enhanced Raman scattering (SERS) for the ultra-sensitive bio-chemical detection even to a single molecular level.…”

Toward biomaterial-based implantable photonic devices

“…These plasmonic structures can be used as sensors or to enhance fluorescence [120]. A spectral shift sensitivity up to 1200 nm/RIU has been demonstrated for sensing glucose [121]. …”