3D/1D MoS2 flower-like microspheres@Au nanowires heterojunction SERS platform with all components simultaneously & synergically contributing to each enhancement effect of electromagnetic and chemical mechanisms

Constructing a heterogeneous structure with the combined contribution of electromagnetic (EM) and chemical (CM) mechanisms, while enabling all components to contribute to each mechanism, is an effective strategy for developing new high-performance surface-enhanced Raman scattering (SERS) substrate. In this work, a novel 3D/1D MoS 2 flower-like microspheres@Au nanowires (MoS 2 FMs@Au NWs) heterojunction SERS matrix platform is successfully developed through morphology regulating and interface engineering strategies. The enhancement factor of SERS matrix is as high as 3.97 × 10 9 . The theoretical simulations and experiments reveal the combined contribution of EM and CM mechanisms. The dual EM effects (Mie resonance triggered by 3D MoS 2 FMs and hotspot effect of high-density Au NWs customized by highly ordered MoS 2 ) and the multidimensional CM contributions (high-efficiency carrier separation of MoS 2 triggered by heterostructure and high carrier utilization rate from hot electron excitation of Au NWs) can be synchronously achieved for boosting SERS activity of the heterojunction. More meaningfully, the developed SERS matrix can realize an ultra-sensitive detection for trace fungicide residues (crystal violet and malachite green) in real water system. This discovery provides new insights and perspectives for developing novel function-customized SERS substrates, aiming to advance the practical application of SERS technology.