Tunable dual-functional SERS-photoluminescence detection enabled by metal phthalocyanine/MoS2 composites: Central metal atom effects

Surface-enhanced Raman scattering (SERS) and photoluminescence (PL) synergism offer unprecedented analytical capabilities, yet existing substrates face challenges in balancing sensitivity and signal differentiation. Transition metal dichalcogenides like MoS 2 show promising SERS and PL performance but suffer from limited charge transfer due to their ultra-flat surfaces. In this study, we explored metal phthalocyanine (MPcs)/MoS 2 heterostructures to synergize chemical enhancement and localized plasmon resonance, with the central metal atom (Cu, Zn, Co) acting as a key modulator. Notably, the CuPc/MoS 2 substrate exhibited exceptional SERS and PL performance, achieving a low limit of detection (LOD) of SERS for methylene blue (MB) and rhodamine 6G (R6G) molecules up to 10 −11 and 10 −13 M with enhancement factors (EFs) 1.99 × 10 7 and 3.52 × 10 9 , respectively, outperforming ZnPc- and CoPc-based systems. Furthermore, it showed an optimal LOD of 4.5 × 10 5  ng/L for 100 nm polystyrene nanoparticles. This study elucidates the influence of the central metal atom in MPcs on the SERS and PL properties of MPc/MoS 2 composites. The results are crucial for the development of efficient SERS substrates and the understanding of the fundamental mechanisms of SERS and PL enhancement, paving the way for development of advanced semiconductor based dual-functional SERS and PL platforms.