A highly tunable and fully biocompatible silk nanoplasmonic optical sensor.
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.
['Lee|Myungjae|M|', 'Jeon|Heonsu|H|', 'Kim|Sunghwan|S|']
D001672:Biocompatible Materials D015374:Biosensing Techniques D006046:Gold D008670:Metals D047011:Silk D020349:Surface Plasmon Resonance
Silk fibroin hydrogel biocompatible device metal−insulator−metal resonators plasmonic sensor surface plasmon