LAUSR

Abstract The construction of sensitive materials for trace detection is significant for various applications, including structure analysis, environment monitoring, and biological analysis. A critical challenge is the construction of materials with a combination of high sensitivity, excellent reliability, and good reusability. Here, we describe a hierarchical Ag–TiO2 composite that can provide three-dimensional hot spots for local electric field enhancement. This substrate can offer stable surface-enhanced Raman scattering (SERS) signal with an absolute intensity that is ∼51 times higher than that of conventional Ag substrate. The SERS signal from the substrate is highly homogenous over a wide region, without any obvious peak fluctuations. Moreover, the composite can be regenerated through an in situ photocatalytic reaction of TiO2. This innovative, recyclable SERS substrate can provide an efficient platform for in situ structure analysis and trace detection.