Fabrication of blue silver substrate with 10 nm grains by an electrochemical deposition and application in SERS

Nanosized-silver substrates with smooth surface and fine particles were fabricated by a non-cyanide pulse electrochemical deposition. The electrochemical behavior of silver electrochemical deposition was investigated with a series of electrochemical methods. Cyclic Voltammetry and chronopotentiometry showed that the overpotential was significantly reduced when silver ions were continuously deposited on the silver layer. During deposition, the nucleation mechanism gradually changed from the progressive nucleation to the instantaneous nucleation with the negative shift of potential. The effect of pulse period θ on the Surface Enhanced Raman Scattering performance of the substrate was investigated. Combined with Scanning Electron Microscope, X-ray diffraction, 2D SERS Mapping and Raman spectrum, the pulse period θ was optimized. The enhancement effect of the substrates was relatively uniform, and the enhancement factor for rhodamine 6G was 5.34 × 10⁶, the detection limit could be as low as 1.0 × 10⁻¹³ mol·L⁻¹. The optimized substrate obtained good linear range and low detection limit in the detection of contraband pigment sunset yellow, indicating that the substrate may have a good application prospect in the actual detection.