Silver Nanobead-Decorated Knurled Aluminum for Sensitive SERS Detection of Amoxicillin

Abstract Development of reproducible and cost-effective surface-enhanced Raman scattering (SERS) substrates with high sensitivity remains a major challenge for trace-level detection of antibiotic contaminants. Herein, we report a facile fabrication of silver nanobead-decorated knurled aluminum (AgNBs@KA) substrates using a silver mirror reaction for the sensitive detection of amoxicillin (AMX). The knurled aluminum surface enables the uniform growth of Ag nanobeads and the formation of abundant plasmonic hotspots for enormous SERS enhancement. Structural and morphological analyses confirmed the successful formation and homogeneous distribution of Ag nanobeads on the substrate. The optimized AgNBs@KA substrate exhibited excellent SERS performance with a detection limit of 10−9 M for AMX and an analytical enhancement factor of 2.99 × 108, along with a good signal reproducibility of 8.2% and storage stability. The enhanced sensing performance is attributed to the synergistic effect of the hierarchical aluminum surface and densely distributed Ag nanobeads. This work demonstrates a simple, low-cost, and scalable plasmonic platform for rapid antibiotic detection and practical SERS-based sensing applications.