Multifunctional engineering on the ultrasensitive driven-dual plasmonic heterogenous dimer system of 1D semiconductor for accurate SERS sensitivity and quantitation

Self-assembled functional nanomaterials with electromagnetic (EM) hot spots and chemical (CM) enhancement have been recognized as a key in surface-enhanced Raman scattering (SERS) analysis. Herein, a dual-hybrid plasmonic coupling SERS sensor composed of rutile TiO2 nanorod arrays (r-TNRs), Au nanospheres (AuNSs), and Ag nanocubes (AgNCs) has been designed to achieve ultrasensitive detection and obtain unique molecular fingerprints. The AgNCs/AuNSs/r-TNRs-based SERS chip shows an extremely promising SERS enhancement factor (EF) of 1.2 ×1011, detectability at sub-picomolar concentrations (down to the single-molecule level, 10-13 M), and excellent signal reproducibility with a relative standard deviation (RSD) of 3.4 %. Furthermore, this system has been applied for fingerprint detection in complex mixtures, demonstrating impressive specificity and accuracy. The photocatalytic decomposition efficiency of the AgNCs/AuNSs/r-TNRs platform reaches approximately ∼99 % within 20 min. Additionally, the Raman intensity of crystal violet only declined by 15 % after 21 days, illustrating the outstanding stability of the as-proposed ternary SERS sensor.