Mesoporous Ag–TiO2 based nanocage like structure as sensitive and recyclable low-cost SERS substrate for biosensing applications

A highly sensitive SERS substrate based on a mesoporous Ag–TiO2 thin film for the detection of dye molecules

“…1(c), varies mainly from 20–60 nm, implying that the film is mesoporous. According to our previous report, 26 if the Ag coating thickness is increased, the Ag nanostructure will appear as irregular islands on the TiO 2 film. In addition, the porosity is reduced with the increase in the thickness of Ag.…”

“…The fabrication details of the Ag–TiO 2 SERS substrate is reported in our previous study. 26 Briefly, the glass plates were cleaned using a soap solution, ultrasonicated and rinsed in deionised water and finally boiled in isopropanol. The titania paste was prepared by taking TiO 2 nanopowder (0.8 mg), polyethylene glycol (0.6 ml) and acetic acid (0.6 ml).…”

“…The optimised thickness of Ag was found to be 10 nm for maximum SERS activity from previous studies. 26…”

“…Our previous reported work thoroughly evaluated a detailed study of the enhancement factor (EF), reproducibility and self-cleaning ability of the fabricated film. 26 The porous, nanocage structure of the TiO 2 film contributes a greater surface area for the growth of Ag and more surface for reactions and diffusion in photocatalytic activity. 26 In this study, we investigate the Raman activity of the Ag-TiO 2 nanocage SERS film using two different excitation lasers of wavelengths 514.5 nm and 785 nm, respectively.…”

“…26 The porous, nanocage structure of the TiO 2 film contributes a greater surface area for the growth of Ag and more surface for reactions and diffusion in photocatalytic activity. 26 In this study, we investigate the Raman activity of the Ag-TiO 2 nanocage SERS film using two different excitation lasers of wavelengths 514.5 nm and 785 nm, respectively. The FDTD simulation is also used to calculate the maximum Raman enhancement for various excitation lasers.…”