▎ 摘　　要

NOVELTY - Raman-detectible composition comprises at least two different Raman-active two-dimensional (2D) materials. USE - The composition is useful in formulation, ink and substrate for tagging a substrate, generating code based on the 2D material content of material, apparatus for verifying the authenticity of an article (all claimed) and robust industrial application. ADVANTAGE - The composition: utilizes nanomaterial-containing material which encodes a unique fingerprint/code that can be determined using Raman spectroscopy and used to verify the authenticity of the product; exhibits high absorbance relative to their thickness (e.g. 2.3% per monolayer in graphene and 15% in molybdenum disulfide) meaning that they absorb an appreciable fraction of the incident light even in thin coatings or at low loadings in matrix materials, this high monolayer absorbance is coupled to the high polarizability of the crystal structures and confinement-induced increases in the phonon density of states, which results in strong Raman scattering in these materials; exhibits minimal cohesion under abrasion; and improves the robustness of the dried films. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a formulation comprising the composition and a binder; (2) a substrate comprising the composition, where the composition is homogeneously dispersed within the substrate, and the substrate is not a metal or the composition is on the surface of the substrate, optionally and the composition also comprises a binder; (3) tagging (M1) a substrate with the composition, comprising dispersing the composition within the substrate, where the substrate is not a metal or applying the composition to the surface of the substrate, optionally where the composition also comprises a binder; (4) analyzing (M2) a substrate or formulation for the presence of the composition, comprising (i) subjecting the substrate or formulation to Raman spectroscopy, and (ii) analyzing the Raman spectrum for the presence of a Raman signal that is characteristic of the composition; (5) generating (M3) code based on the 2D material content of a material, comprising measuring and obtaining the Raman spectrum of a material comprising the composition, comparing the obtained Raman spectrum with reference data for each of the different 2D materials in order to determine the presence, and optionally the quantities, of the different 2D materials and generating a code based on the presence, and optionally the quantities, of the different 2D materials; (6) an ink comprising the formulation, and a liquid carrier, preferably where the binder is a polymer; and (7) an apparatus for verifying the authenticity of an article, comprising a Raman spectrometer, the spectrometer comprising a laser light source and a detector, an electronic data store for storing known Raman reference data of at least two different Raman-active 2D materials, an electronic data processor for comparing the Raman spectrum obtained by the spectrometer and the Raman spectra in the electronic data store and an output device for indicating to the user either a code derived from the obtained Raman spectrum or an indication of the authenticity of the article.