Facet-Directed Growth of Spiky Gold Datura-Shaped Nanoparticles as SERS Platforms Enabling the Detection of Psychotropic and Explosive Molecules

Rationally engineered anisotropic plasmonic nanostructures offer exciting opportunities for molecular-level sensing. Here, we report the surfactant-guided synthesis and application of gold nanodaturas (Au-NDs)─a class of spike-covered, seedpod-like nanostructures─for flexible, ultrasensitive surface-enhanced Raman scattering (SERS) platforms. The anisotropic growth of Au-NDs was achieved via faceted overgrowth on pentatwinned seeds in a binary surfactant environment, cetyltrimethylammonium bromide (CTAB) and benzyldimethylhexadecylammonium chloride (BDAC), enabling precise control over particle morphology and size. Molecular dynamics simulations provided mechanistic insight, revealing that surfactant micelle density and counterion effects modulate facet-selective deposition, with dense CTAB/BDAC coverage on Au(110) facets suppressing growth and promoting edge-directed elongation. This atomistic understanding explains the emergence of the spiky nanodatura morphology. Exploiting their intense plasmonic hotspots arising from the sharp tips, Au-NDs were immobilized on both Whatman paper and thermally wrinkled shrink films to fabricate flexible SERS substrates. The shrink-induced nanoscale clustering significantly enhanced SERS activity, enabling detection of 1,4-benzenedithiol down to 10 –16 M. Furthermore, real-world analytes, including Δ 9 -tetrahydrocannabinol (THC) and picric acid (TNP), were detected without labels or surface modification, with high spectral reproducibility. Together, our integrated experimental–computational approach offers a robust, scalable route to tunable plasmonic architectures for field-deployable chemical sensing. These nanodatura-enabled SERS platforms hold promise for forensic diagnostics, drug screening, and explosive residue detection in point-of-care and security applications.