Patent ID: 7956997

Claim:
A method for detecting an ingredient in a food product, comprising: establishing a spectral signature in a Raman spectrum obtained from a chemical substance; allowing a food sample solution obtained from a food product to come into contact with a first nano-scale surface structure in a first sensor; illuminating the food sample solution and the first nano-scale surface structure on the first sensor by a laser beam; scattering the laser beam by the food sample solution and the first nano-scale surface structure to produce a scattered light; obtaining a first Raman spectrum from the scattered light using a spectral analyzer; and identifying the spectral signature around a predetermined wavelength in the first Raman spectrum to determine the existence of the chemical substance in the food product, wherein the step of establishing comprises: allowing a reference sample solution containing the chemical substance to come to contact with a second nano-scale surface structure in a second sensor; and obtaining a second Raman spectrum from the reference solution and the nano surface to establish the spectral signature in the Raman spectrum for the chemical substance; wherein the spectral signature includes at least one spectral peak around the predetermined wavelength in the first Raman spectrum; and wherein the step of identifying comprises: determining if the spectral peak in the first Raman spectrum or a signal-to-noise ratio for the spectral peak is above a pre-determined threshold value; and positively identifying the chemical substance if the spectral peak or the signal-to-noise ratio is above the pre-determined threshold value.