Preparation of Thermo-Sensitive Molecular Imprinted SERS Substrate with Robust Recyclability for Detection of Ofloxacin

Abstract

To this day, the preparation of surface-enhanced Raman spectroscopy (SERS) substrates with high sensitivity, selectivity, and stability has been the bottleneck to realizing SERS-based quantitative analysis in practical applications. In this paper, a thermo-sensitive imprinting SERS substrate material (TM@TiO2@Ag) is developed with a uniform structure and morphology, a controllable “hot spot” and photocatalytic regeneration. The as-prepared TM@TiO2@Ag nanocomposite is characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, dynamic light scattering, ultraviolet–visible (UV-Vis) spectroscopy, etc. After the effects of its thermo-sensitive property on localized surface plasmon resonance (LSPR) and SERS signals are investigated, this nanomaterial is used as the Raman-enhanced substrate for rapid and trace detection of ofloxacin (OFL) in water. It is found that, with the aid of unique structure and composition, temperature sensitivity, and molecule imprinting, the SERS sensor possesses considerably strong anti-interference ability not only to structure-unlike but also to structure-like co-existing substances, extremely low detectable concentration of 1.1 × 10−11 M for OFL at 1397 cm−1, as well as excellent reusability due to its photocatalytic degradation to target analytes.