Highly sensitive, reproducible, and stable core–shell MoN SERS substrate synthesized via sacrificial template method

Molybdenum nitride is a promising candidate for surface-enhanced Raman scattering (SERS) substrates due to its high conductivity, surface plasmon resonance, and chemical stability. Core-shell structures possess unique physical and chemical properties, such as high-volume ratio, low density, short diffusion length, and high load-bearing capacity, making them favorable for SERS applications. In this research, core–shell MoO₃ is first synthesized as a precursor oxide using a sacrificial template method, and core–shell MoN microspheres are successfully prepared via subsequent nitriding. As a representative transition metal nitride, the obtained core–shell MoN nanospheres show strong localized surface plasmon resonance and SERS effects. Using these MoN microspheres as Raman substrates allows a range of highly targeted compounds to be accurately detected, and the detection limits for this non-precious-metal substrate morphology are exceptionally high, reaching 10⁻¹⁰ M. In addition, MoN nanospheres exhibit excellent resistance to acid–base corrosion, oxidation, and radiation, thus rendering them suitable for use as substrates in harsh environments.