Facile interfacial synthesis of gold micronails with adjustable length and roughness and their superior SERS properties for the detection of p-aminothiophenol

Au hierarchical architectures with special morphology and structures are strongly desired in varied applications. Herein, a simple synthesis method was developed for the one-step preparation of Au micronails (MNs) at the planar liquid-liquid interface under mild conditions. The well-defined Au MNs were grown and constructed at CHCl₃–H₂O interface at room temperature using aniline in CHCl₃ as reducing agent and HAuCl₄ in H₂O as precursor and no surfactant or seed is required. The intriguing Au MNs with rough surface consist of big heads and thin rods, just like iron nails in outline. Furthermore, through simple changing the reagent concentrations, the length and surface roughness of Au MNs can be adjusted conveniently. The effects of a series of factors on the morphology and structure of the products are studied in detail. With p-aminothiophenol as a molecular probe, the as-obtained Au MNs all exhibit dramatically improved surface enhanced Raman scattering sensitivity and high reproducibility, the enhancement factor and limit of detection of Au MNs are 5.4 × 10⁵ and 1.0 × 10⁻¹⁰, respectively.