Coaxially electrospun TiO2@Au core-shell nanofibers for ultrasensitive and reusable SERS detection of furazolidone

Abstract

We report the core/shell synthesis of TiO2 nanofibers covered with Au nanograins (Au NGs@TiO2 NFs) by the direct coaxial electrospinning method without the need of pre-preparation of Au NGs for the rapid and sensitive SERS detection of furazolidone (FZD). The characterization of the as-synthesized Au NGs@ TiO2 NFs hybrid nanostructure was meticulously examined by diverse microscopic and spectroscopic techniques. The SERS performance of Au NGs@TiO2 NFs for the detection of FZD is verified with the high enhancement factor of 5.96 × 1012 and the limit of detection as low as 3.94 × 10−13 M, which are superior to those reported so far in the literatures. The excellent SERS performance can be attributed to the synergistic effect of electromagnetic enhancement and charge transfer induced in the Au NGs@TiO2 NFs hybrid nanostructure. Besides, the Au NGs@TiO2 NFs display good uniformity and high reproducibility for the FZD detection. In the practical application, the Au NGs@TiO2 NFs based SERS substrate is successfully utilized to detect FZD in food and environmental samples with excellent recovery. The reusability measurement shows that 92.73 % of the original Raman peak intensity is retained after five photocatalytic degradation cycles, which confirms the cost effectiveness of Au NGs@TiO2 NFs in the SERS application. The proposed high-performance SERS substrate has great potential to pave a new avenue in food safety applications, such as detecting antibiotics in real samples.