Surface-Enhanced Raman Scattering Based-Molecular Encoding with Gold Nanostars for Anticounterfeiting Application
Surface-enhanced Raman scattering (SERS) recently joins other optical methods in making novel anticounterfeiting materials due the fact that abundant molecular fingerprint in the Raman spectra can be less susceptible to fraud. To fully using these molecular features, it is critical to make novel nanostructures with increased SERS enhancement and stability. Herein, we synthesized star-shaped gold nanoparticles as SERS substrates and applied various Raman probes with these gold nanostars (Au NSs) to make SERS tags. The encoded molecular information was successfully decoded using principal component analysis (PCA). These colloidal tags can be further stabilized when embedded in polymer matrix. We made a prototype ballpoint pen that can do simple writings with these secret SERS inks.