Fabrication of Scale-like Silver-Nanosheets-Grafted Carbon-Fenced Conductive Silver Nanowires as Effective 3D SERS Substrates

Abstract

The Ag-nanosheets (i.e., AgNST)-grafted carbon-fenced conductive Ag nanowires with 3D scale-like nanostructure was successfully fabricated through a direct chemical reduction method, where the carbon shell was first carbonized onto the suface of Ag nanowires to form an Ag nanowires@carbon (i.e., AgNWs@C) framework, and then the citrate acid which absorbed on the prefabricated AgNWs@C@Ag seeds framework directed Ag ions to be Ag nanosheets to self-assemble into 3D scale-like nanostructures (i.e., AgNWs@C@AgNST). The fabricated nanostructure displayed the sensitive and reproducible surface-enhanced Raman scattering (SERS) responses. The SERS detection for the probing molecule (rhodamine 6G, R6G) with concentration as low as 10–12 mol/L was obtained in a reproducible way, and the average enhancement factor was about 2.33 × 105, which was calculated from the band of 610 cm–1 in the SERS spectrum. It was caused by Ag nanosheets with high density providing abundant “hot spots” to enhance the SERS detection. Bes...