Laser-tunable Raman markers based on glass–ceramic/β-carotene mixtures for advanced anti-counterfeiting applications

Abstract

The need for more reliable authentication methods is rapidly increasing due to the significant economic, social, and security losses caused by the counterfeiting of valuable products. This work explores the possibility of using customizable Raman markers from hierarchical mixtures of feldspar glass–ceramic and β-carotene. The detection signal is based on the combination of Raman spectra of inorganic particles and modifiable Raman spectra of the organic compound by isomerization under laser heating. In this work, the preparation of these Raman markers and the β-carotene isomerization conditions have been established. The laser thermal treatment allows obtaining Raman response distributions in which the altered and unaltered regions can be clearly identified by their differences in the Pearson correlation coefficient. These differences can be used to build the encoding of the response for authentication purposes. Thus, a dual modulation of the Raman response can be obtained: spectral modulation, by adjusting the composition, and spatial modulation, by selectively transforming β-carotene in submillimeter regions, making it possible to create custom patterns in a scalable encoding capacity number of unique encodings for each application.