Flexible Surface‐Enhanced Raman Scattering Substrates: A Review on Constructions, Applications, and Challenges

Abstract Flexible surface‐enhanced Raman scattering (SERS) substrates have recently attracted growing research interests in real‐world applications due to their unique advantage of sensitivity and flexibility. Reviewing the latest progress of flexible SERS substrates is very important for further development of high‐quality detection platforms. Herein, the recent developments of flexible SERS substrates in fabrications and applications are introduced. First, three categories of current flexible SERS platforms including paper‐based SERS substrates, polymer‐based SERS substrates, and inorganic materials‐based SERS substrates are demonstrated in depth. Then, the focus is moved to the applications of flexible SERS substrates. Combining swab strategies, lateral flow strips, paper‐based microfluidics, and in situ detection techniques, flexible SERS platforms provide intriguing applications in various fields. The challenges are also identified for practical applications on account of substrates’ uniformity, quantitative accuracy, multiplex detection ability, and overall cost. It is believed this review will be of help for researchers to design and fabricate flexible SERS substrates with higher performance and lower cost, and finally realize the practical applications.