Diffuse Reflectance Circular Dichroism for the Detection of Molecular Chirality: An Application in Remote Sensing of Flora

Abstract

Terrestrial biochemistry is based upon chiral (handed) molecules, of which only one of the two possible hands is predominantly employed. This biomolecular “homochirality”, may be a universal “signature” of life. Along with all living organisms, plant leaves are constructed from arrays of chiral molecules of a single hand. Through the development of a new spectroscopic approach, Diffuse Reflectance Circular Dichroism in the UV-visible wavelength regions, we have detected this chirality non-invasively from non-specular light scattered by leaves. The characteristic spectra are sensitive to plant species and leaf age/health. The technique may provide a means of remote sensing the state of flora and, at closer range, an indicator of living organisms for interplanetary landers.