Highly Reproducible Surface‐Enhanced Raman Scattering on a Capillarity‐Assisted Gold Nanoparticle Assembly

Abstract

Abstract A facile method based on capillarity‐assisted assembly is used to fabricate high‐performance surface‐enhanced Raman scattering (SERS) substrates employing clean Au nanoparticles (NPs). This method is better than micro‐channel way because the former may supply large‐area uniform assembly and overcome the uneven radial distribution. Such densely‐arranged assembly of Au NPs exhibits high reproducibility and large Raman enhancement factors of 3 × 10 10 , arising from strong electromagnetic field coupling induced by adjacent Au NPs. The spot‐to‐spot SERS signals show that the relative standard deviation (RSD) in the intensity of the main Raman vibration modes (1310, 1361, 1509, 1650 cm −1 ) of Rhodamine 6G at a concentration of 1 × 10 −10 M are consistently less than 20%, demonstrating good spatial uniformity and reproducibility. The SERS signals of sudan dye at a 1 × 10 −8 M concentration also shows high reproducibility with a low RSD of <20%. Further, the assembly substrate is stable, retaining excellent uniformity and sensitivity after storage for months. This assembly strategy integrating the advantages of low‐cost production, high sensitivity, and reproducibility would significantly facilitate practical SERS detection.