Cheap, reliable, reusable, thermally and chemically stable fluorinated hexagonal boron nitride nanosheets coated Au nanoparticles substrate for surface enhanced Raman spectroscopy

In this study, multi-layered fluorinated hexagonal boron nitride nano-sheets (F-BN) coated gold-nanoparticles (AuNPs/glass) SERS-active substrate is presented. Thermal and chemical stabilities with reusability tests of F-BN/AuNPs/glass SERS-active substrate were performed. The AuNPs on glass substrate (AuNPs/glass) was first prepared by combining ion-sputtering technique with a rapid annealing treatment. Second step involved the spin coating of a thin film of F-BN as a shielding layer on AuNPs/glass substrate. It was seen that Raman performance of FBN/AuNPs/glass substrate is more stable and efficient as compared to bare AuNPs/glass substrate under strong chemical and oxidative environments. Moreover, outcome of cycle tests indicated that F-BN as a protecting layer, could recover the long-term stability of the bare AuNPs/glass SERS-active substrate. DFT based calculations were also performed and theory supported our experimental results that R6G on F-BN/glass has higher adsorption capability as compared to BN/glass. Consequently, our proposed multi-layered F-BN is found to be an excellent wrapping material on AuNPs/glass substrate for cost effective production and reliable fabrication of capable SERS. It is also useful for the detection of particular sensing molecules at high temperatures or in extreme acidic conditions that are too complicated to be analyzed by means of conventional SERS. Hence, our proposed method will promote the wider usage of functionalized BN/metal based SERS in multidisciplinary fields.