Surface-Enhanced\nRaman Scattering-Encoded Gold Nanostars\nfor Multiplexed Steganographic Anticounterfeiting Labels

Abstract

Steganography is a technique that encrypts information\nby hiding\nit in another medium, such as video, audio, images, and text. The\nprincipal purpose of steganography is to conceal the existence of\ninformation so that it cannot be easily recognized by a third-party\nduring transmission, which guarantees information security. Surface-enhanced\nRaman scattering (SERS) probes contain rich spectral information.\nWith the increasing application of SERS in optical anticounterfeiting\nfield, the development of SERS labels with superior encoding capacity\nhas become research hotspot. In this study, we mixed Au nanostar SERS\nprobes with ordinary commercial ink to obtain SERS ink for optical\nsteganography and anticounterfeiting labels. Au nanostars have abundant\ntip “hotspots” and large specific surface area, and\nstrong SERS signals can be manufactured by modifying Raman molecules\non its surface. Fifteen different kinds of Raman molecules were chosen\nas a demonstration, and the signal molecules were tightly modified\non the surface of Au nanostars by dopamine encapsulation and then\nmixed with ordinary ink to obtain SERS ink with different signals.\nThen, the information recorded by SERS ink was extracted and interpreted\nby a micro-Raman imaging system. In addition, SERS ink can also be\nused in barcodes and quick response (QR) codes, and the possibility\nof being cracked can be greatly reduced through Raman signal multiplexing.\nDue to the advantages of SERS ink, such as simple preparation, good\nphotostability, long-term stability, multiplexing steganography, and\nconvenient use, we believe that Au nanostar-based SERS ink has broad\nprospects in the application of optical steganography and anticounterfeiting.