Patent ID: 8638434

Claim:
A method comprising: detecting a chiral property of a sample from a fluorescent emission of the sample, wherein the detecting comprises: irradiating the sample with an excitation beam; varying a polarization angle of the excitation beam; and measuring an intensity of the fluorescent emission as a function of a polarization angle; obtaining an extended anisotropic expression A(θ) defined as: A ⁡ ( θ ) = I θ , θ - I θ , θ + 90 ⁢ ° I θ , θ + 2 ⁢ I θ , θ + 90 ⁢ ° wherein I is the intensity of the fluorescent emission measured at an excitation polarization angle θ (first subscript of I) and an emission polarization angle θ or θ+90° (second subscript of I); and obtaining a chirality vector from the fluorescent emission based on the extended anisotropic expression; wherein the obtaining a chirality vector comprises obtaining asymmetric factors at a plurality of different fluorescent emission polarization angles; wherein the plurality of different fluorescent emission polarization angles include three angles; and wherein the obtaining asymmetric factors comprises: for chiral fluorescent molecules: obtaining an extended anisotropy (X) at different excitation and fluorescent emission polarization angles; and obtaining a reciprocal of the extended anisotropy (X′) at different excitation and fluorescent emission polarization angles; for achiral fluorescent molecules: obtaining an extended anisotropy (Y) at different excitation and fluorescent emission polarization angles; and obtaining a reciprocal of the extended anisotropy (Y′) at different excitation and fluorescent emission polarization angles; and calculating the asymmetric factor (X-X′)/(Y-Y′).