Flexible surface-enhanced Raman scattering active substrates based on carbon materials

Surface-enhanced Raman scattering (SERS) technology offers a highly sensitive and non-invasive approach for the label-free detection of a wide variety of low-concentration molecules. In contrast to conventional rigid SERS substrates and typical flexible options like those made from paper or polymers, flexible carbon-based SERS substrates offer superior mechanical strength, chemical stability, sensitivity, better biocompatibility, and a notable ability to quenching fluorescence. Because of these advantages, flexible carbon-based SERS substrates have been getting a lot of attention lately. In this review, we systematically summarize and discuss the recent advances in flexible carbon-based SERS substrates. Firstly, the review illustrates the enhancement mechanisms of SERS. Then, pure carbon materials with SERS activity are introduced by dividing them into four categories by dimensions. Subsequently, the strategies for improving the SERS responsiveness of pure carbon materials with good flexibility as substrates are elaborated specifically, mainly including doping and the construction of composite structures. Next, their applications in the field of food safety, environmental monitoring and biomedicine are mainly reviewed. Finally, the current challenges and future trends of flexible carbon-based SERS substrates are discussed.