Fig. 4From: SERS Detection of Biomolecules by Highly Sensitive and Reproducible Raman-Enhancing Nanoparticle Array a SERS spectra of adenine (10−4 M) on AgNP/AAO substrate and Ag nanoparticles electrochemically plated on the aluminum (Al) thin film (AgNP/Al) substrate (without AAO template) by averaging seven spectra taken at different spots of the substrate, respectively. b Top-view scanning electron microscope image of AgNP/glass substrateBack to article page