Highly sensitive multiplex-detection of surface-enhanced Raman scattering via self-assembly arrays of porous AuAg nanoparticles with built-in nanogaps

•A novel SERS sensing platform based on self-assembly arrays of porous AuAg NPs with nanogap is fabricated.•The intelligent SERS platform has demonstrated high sensitivity and multiplex sensing of R6G and CV molecules.•The SERS enhancement factor of ~7.8 × 106, RSD of<6.5% and LOD of 2.37 ×10−9 M concentration have been achieved.