Synthesis of the 3D AgNF/AgNP arrays for the paper-based surface enhancement Raman scattering application

Paper-based SERS sensor has attracted considerable attention recently, resulting from the separation, aggregation and high sensitive detection of biomolecules. However, optical losses, caused by the holes or “vase”-like defects, affect the overall intensity of the electromagnetic (EM) coupling and then the Raman signal. Silver nanoflowers (AgNFs) connected with silver nanoparticles (AgNPs) arrays are proposed and firstly obtained onto such “vase” surface to enhance the EM coupling. AgNFs are easily self-assembled on the defects, and the closed packed AgNPs can be formed on the other area. Multiple cascaded amplification mechanisms (localized surface plasmon mode and optical standing waves or refraction) are used to promote the EM magnification. Such paper card is also exploited successfully as an integrated platform, allowing for ultra-sensitivity (1 × 10−19M) CV and (1 × 10−20M) R6G detection.