Background

Many essential molecules characterizing a virus or bacteria can exist in two mirror-image forms, referred to as “left-handed” and “right-handed”. The structure of the proteins or RNA of SARS- COV-2 () shows a homochirality. The two enantiomers of the protomers in SARS-COV-2 will interact differently with circularly polarized light or chiral photons and form the basis of the optical technique for chiral molecular sensing. Thus, SARS-COV-2 can be detected by the change in the differential optical absorption of left and right circularly polarized light. The RNA or protomers of SARS-COV-2 will preferentially absorb one direction of circularly polarized light which can be measured by circular dichroism (CD) spectroscopy. The CD depends on the chirality of the enantiomers and can also be enhanced by the chirality of the light source.

Technology Overview

Chiral nanostructures are non-superimposable to their mirror image, and produce a different optical response for left circularly polarized (LCP) & right circularly polarized (RCP) light. Hindered by their small chiral asymmetry & electromagnetic interaction volume, naturally occurring chiral structures such as amino acids, DNA, and RNA exhibit low CD signals, which imposes limits on their detectability. This can be resolved by coupling these naturally occurring structures to artificially engineered plasmonic nanostructures under resonant excitation. Chiral plasmonic metamaterials exhibit inherent CD signals whose amplitude depends on the degree of chiral asymmetry of their geometry & thus presents an avenue for designing & manipulating nanoscale chiroptical effects. Researchers at UNT have designed a yin-yang shaped spherically symmetric chiral structure to specifically target SARS-COV-2 ().

Benefits

Tunable resonant spectrum capable of targeting specific applications
Improved spectroscopy techniques, photocurrent generation, & bolometry
Plasmonic metamaterials strongly enhance molecular CD signal & even displace it to longer wavelengths due to the interaction of the strong resonant plasmonic near- field with the chiral biomolecules

Plasmonic Meta-Surface Based Molecular Sensors

IP Status

Seeking