Au–Ag bimetallic nanoparticles: Synthesis, structure, and application in sensing

Biosensors are crucial for detecting various analytes relevant to bioanalytical applications. To enhance the specificity and sensitivity of biosensors, bimetallic nanoparticles (BNPs) have been utilized, which demonstrate significant potential for sensing applications owing to their constituent materials’ inherent properties, small size, unique architectural features, and biomimetic behavior. Among BNPs, Au–Ag BNPs are promising for sensing applications owing to their small size, high sensitivity, and distinctive characteristics. Herein, we first briefly present the development of Au–Ag BNPs and discuss the fundamentals. Subsequently, we present the relationship between the synthesis method and structure of Au–Ag BNPs. Furthermore, recent advancements in Au–Ag BNPs are highlighted for their role in enhancing biosensors, particularly for electrode modifiers, signal amplifiers, and recognition materials. Finally, we propose several existing challenges and summarize insights pertaining to the potential development of Au–Ag BNPs for biosensing applications.