Fabrication of Surface-enhanced Raman Spectroscopy (SERS) - Active Electrodes by Silver Sputtering Deposition for Electrochemical SERS Analysis

SERS-active screen-printed electrodes (SPEs) are extensively applied for electrochemical SERS biosensors with the advantages of portable, inexpensive cost, fast measurement, and sensitive detection. In our work, a useful fabrication method of sputtering deposition for SERS-active SPEs was proposed. Two kinds of working electrodes of SPE which were carbon electrode and gold electrode were successfully deposited by silver nanoparticles. Besides, the sputtering experiments of different substrates (paper, glass epoxy and polyethylene terephthalate) of the SPE were also conducted. The comparison of SERS enhancement of rhodamine 6G (R6G) on different kinds of SERS-active SPEs was introduced. In addition, the relationship between the surface roughness and SERS enhancement has been investigated. The enhancement factor (EF) of Ag/carbon and Ag/gold electrode were estimated as 2.8x10(5) and 2.2x10(7), respectively. From the SERS experiments, the lower background noise of SERS signals could be observed through sputtering deposition method compared with the citrate reduction method. Furthermore, spectro-electrochemical analysis of uric acid was studied. The SERS signals were strongly increased upon the modulation of the applied voltage. These results demonstrated the applicability of this mass producible fabrication method for producing SERS-active SPEs, as well as, highlighting the future potential of commercial bio-applications.