Surface-enhanced Raman scatting substrates fabricated by combining chemical assembly and electrodeposition methods

We reported a method to prepare SERS substrates with a high and uniform SERS activity by combining chemical assembly and electrochemical deposition methods. We systematically investigated the effect of the electrode potential on the surface morphology of the Au nanoparticles on the ITO surface. It is found that An nanoparticles with very uniform structure and proper electromagnetic coupling can be obtained by electrodeposition at -0.04 V (vs. SCE) for 5 min. In situ electrochemical UV-Vis absorption spectroscopy was used to monitor the deposition process by measuring the absorption spectra. A new peak between 600 and 700 nm was observed in the UV spectra during the electrochemical deposition process, which can be used as a measurement of whether and how the electromagnetic field of nanoparticles couples. SERS mapping was performed to demonstrate that the substrate was very uniform with a signal deviation less than 20%, meeting the standard for commercial SERS substrates.