SERS detection of antibiotics using dual plasmonic and charge transfer enhancement mechanism of Ag@MoS2 core-shell nanocomposites

• Ag@MoS₂ core–shell nanocomposites were successfully synthesized via a two-step scalable method. • Dual plasmonic (Ag) and chemical charge transfer (MoS₂) mechanisms enhanced SERS performance. • Achieved ultra-trace antibiotic detection limits down to 10⁻¹⁰ M for Levofloxacin and Tetracycline. • Ag@MoS₂ nanocomposites exhibited approximately threefold higher SERS enhancement compared to AgNPs. • The proposed substrate shows great potential for sensitive environmental and clinical sensing applications. The increasing global threat of antibiotic resistance highlights the need for rapid, sensitive, and non-invasive detection methods in biological and environmental samples. In this study, we synthesized Ag@MoS₂ core-shell nanoparticles and evaluated their performance as a substrate for surface-enhanced Raman spectroscopy in detecting antibiotics at trace levels. The Ag@MoS₂ nanocomposites demonstrated significant Raman signal enhancement due to the synergistic effects of the plasmonic properties of silver and chemical enhancement via charge transfer from the MoS₂ shell. Using Rhodamine 6G as a model molecule, we achieved an impressive detection limit of 10⁻¹⁰ M under both 532 nm and 785 nm excitation, with the latter offering enhanced sensitivity for biological applications. The Ag@MoS₂ core-shell nanocomposites demonstrated a threefold increase in SERS enhancement compared to silver nanoparticles, highlighting their superior performance in amplifying the Raman signal. Additionally, the ability of Ag@MoS₂ to detect antibiotics, specifically Levofloxacin and Tetracycline, at concentrations as low as 10⁻¹⁰ M under 785 nm excitation was demonstrated (surpassing existing SERS-based sensors reported experimentally). The results highlight the excellent sensitivity and potential of Ag@MoS₂ as a powerful platform for SERS-based antibiotic detection. This offers significant promise for environmental monitoring, clinical diagnostics, and combating the growing issue of antibiotic resistance.