Template growth of Au/Ag nanocomposites on phosphorene for sensitive SERS detection of pesticides

We report template growth and dense packing of noble metallic nanoparticles (NPs) on few-layer phosphorene for sensitive surface-enhanced Raman scattering (SERS) detection. Phosphorene obtained by electrochemical exfoliation serves as both the template and reductant in the fabrication of noble metallic NPs which are dispersed on phosphorene without aggregation or pile-up. The BP/Ag/Au and BP/Au/Ag nanocomposites with a nanogap structure exhibit excellent SERS sensitivity and reproducibility with respect to Rhodamine 6G. The BP/Au/Ag nanocomposite is further utilized as the SERS substrate for the detection of two fungicides, thiabendazole and thiram, and detection limits of 10^-7 and 10^-8 M are achieved. Template growth of Au/Ag nanocomposites is demonstrated to be a green strategy for the fabrication of SERS substrates and has large potential in applications such as pesticide detection.