Effect of Voltage and Ag Concentration on the Formation of Ag Nanostructures on TiO2 Nanotubes

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive technique for detecting heavy metals through the plasmonic effect of metallic nanoparticles. In this study, TiO2 nanotubes were used as substrates due to their stability, large surface area, and ordered morphology. Silver nanostructures were electrodeposited to enhance the SERS response by generating hot spots. The influence of voltage and Ag concentration on electrodeposition was analyzed using methylene blue (1 × 10−5 M) as a probe molecule. Higher voltages and concentrations promoted dendritic growth, reaching Raman intensities above 70,000 a.u., optimizing sensitivity. All experiments were conducted in triplicate to ensure reproducibility.