A microfluidic platform for minute-scale synthesizing Au@Ag nanocubes

Noble metal nanoparticles are enduring primarily because of their unique Localized Surface Plasmon Resonance (LSPR) properties, which make them exciting for medical testing, biosensing, and other applications. The LSPR properties of nanoparticles with different shapes and different structures vary. The sharp edges of the cubic structure enable stronger LSPR performance making it more versatile for diverse applications. However, the fast and stable controlled synthesis of cubes, an anisotropic nanoparticle, has been an obstacle for researchers. Microfluidics has a reaction space that matches the scale of the nanoparticles, and the efficient heat and mass transfer capability in the tiny confined space ensures that the synthesis reaction proceeds more efficiently and reliably. Herein, we designed a microfluidic platform for the controlled synthesis of Au@Ag nanocubes, which can synthesize core-shell nanocubes of uniform shape and size in 15 min. Moreover, both Raman probe methylene blue and antibiotic sulfadiazine were detected using this material as a substrate for SERS detection, obtaining satisfactory results (10 −10  M and 10 −7  M, separately).