Handheld chem/biosensor using extreme conformational changes in designed binding proteins to enhance surface plasmon resonance (SPR)

摘要

We present research results centered on development of a highly sensitive handheld chem/biosensor device using a novel class of engineered proteins, designed to undergo extreme conformational changes upon binding their target, which in turn cause extreme changes in refractive index in the protein layer. These proteins are attached to a detector chip with a structured metasurface, to translate the refractive index change into an enhanced shift in surface plasmon resonances (SPR), thereby improving the sensitivity of the overall detector relatively to current commercially available SPR systems. Theoretical calculations have demonstrated the potential of the conformational changes in the engineered proteins to provide the desired change in refractive index. A plasmonic chip with a simple grating metasurface structure was designed to maximize the SPR shift. A prototype chip and a prototype for the overall device housing were fabricated with the inclusion of all other required (commercially available) optical components. The proposed device holds considerable promise as a low-cost, highly sensitive, field-deployable detection system for chemical and biological toxins.