Chemical-etched silver nanowires with tunable rough shape for surface enhanced Raman scattering

Breaking the limitation of smooth silver nanowires (Ag NWs) in forming sufficient “hot spots” is a crucial step to push them into practical surface enhancement Raman scattering (SERS)-based detection. Herein, Ag NWs with various etched configurations were developed by utilizing different amounts of aqua regia as etchant at room temperature . Compared with the smooth Ag NWs, more electromagnetic “hot spots” were enabled by the etched one, which exhibited better sensitivity and uniformity in SERS signals. The limit of detection (LOD) for 2-naphthalenethiol (2-NAT) obtained from the optimized substrate could reach 8.3 × 10 −10 mol/L and the relative standard deviation (RSD) was 6.8%. The maximum enhancement factor (EF) value obtained as 3.34 × 10 6 was even three times higher than that of the smooth one. Finally, an ultra-sensitive detection of thiram with a lowest detectable concentration of 4 × 10 −8 mol/L was facilitated by the optimal etched Ag NWs.