• • The 2D Ag2Te nanosheets exhibit quasi-metallic properties with a low resistivity of 2.8 × 10−4 Ω cm and a high free electron density of 4.15 × 10^22 cm−3, enabling a strong surface plasmon resonance band in the visible region, which is critical for electromagnetic enhancement in SERS.
• • The SERS substrate achieves an ultra-low limit of detection (LOD) of 10−10 M for methylene blue (MB) with an enhancement factor (EF) of 2.6 × 10^7, surpassing most semiconductor-based substrates and rivaling noble metals, thus offering a cost-effective alternative for trace-level detection.
• • Real-sample detection demonstrated high accuracy and reliability with recoveries ranging from 91.5% to 108.3% for various target molecules, indicating the substrate's practical applicability in complex matrices.
• • The synthesis via a simple one-step redox reaction using 2D Te nanosheets as templates ensures structural simplicity and cost-effectiveness, while the inherent 2D nature provides opportunities for further nanostructural engineering to enhance SERS performance.