Fabrication of Bimetallic Nanodendrites Using the Electrodeposition Technique for the Detection of Molecules at Trace Level by SERS

Plasmonic bimetallic nanomaterials have generated great interest for SERS substrate development due to their high sensitivity for the detection of molecules in trace amounts. The increase in the sensitivity of the Raman signal is strongly influenced by the density of the particles and the morphology of the structures deposited onto substrate. Electrochemical methods offer high control of shape and size. In this work, SERS substrates based on bimetallic AgCu and AgAu nanodendrites on Al substrates were successfully obtained by the simple electrodeposition technique. The SERS effect of AgCu bimetallic nanodendrites showed the detection of 4-aminothiophenol (4-ATP) at ultra-low concentrations such as 1 × 10–15 mol·L−1 with a magnification factor 3.11 × 1012; while the bimetallic AgAu nanodendrites achieved the detection of rhodamine 6G (R6G) at concentrations of 1 × 10–9 mol·L−1 with enhancement factor up to 2.058 × 106. The experimental results obtained are an important contribution of the present research, since they are fundamental for the development of novel nanostructured SERS substrates of ultra-high sensitivity, as well as they promote innovation and the development of structures from simple, sustainable, resilient and especially low cost.