Multifunctional Au–Ag–Cr Nanocomposites: From Multiplex Sensing and Advanced Logic Computing to Scalable Information Protection

Polymetallic nanomaterials have important development potential by integrating the properties and advantages of their components. However, their preparation paradigm urgently needs to be updated to make full use of their characteristics to realize their multifaceted applications. In this study, multifunctional trimetallic gold-silver-chromium nanocomposites (Au-Ag-Cr NCs) were successfully synthesized, and their polymetallic plasmonic absorption properties were used in a variety of applications, from multimode and multianalyte sensing, advanced arithmetic, and reversible logic to long-text information protection. Au-Ag-Cr NCs with Au or Ag nanoparticles anchored on Cr nanobelts were synthesized using Au-Cr nanoseeds, Ag⁺, ascorbic acid as the reductant, and sodium dodecylbenzenesulfonate as the stabilizer. The resulting Au-Ag-Cr NCs exhibited multichannel sensing ability for 2 analytes (Hg²⁺ and hypochlorite), with remarkably improved selectivity and sensitivity when analyzing combined channels. Multiresponsiveness of Au-Ag-Cr NCs to diverse substance combinations underpins input-output mapping relationships, enabling advanced molecular logic computations (such as arithmetic and reversible logic). By digitizing its intrinsic sensing and response mechanisms, advanced molecular information protection (including encoding, encryption, and information concealment) for extended text were successfully implemented. This work not only offers novel insights into the design and multifunctionality of multicomponent nanocomposites but also paves the way for a new paradigm in molecular information technology that integrates sensing, logic processing, and information security.