Toward Flexible Surface‐Enhanced Raman Scattering (SERS) Sensors for Point‐of‐Care Diagnostics

Surface‐enhanced Raman scattering (SERS) spectroscopy provides a noninvasive and highly sensitive route for fingerprint and label‐free detection of a wide range of molecules. Recently, flexible SERS has attracted increasingly tremendous research interest due to its unique advantages compared to rigid substrate‐based SERS. Here, the latest advances in flexible substrate‐based SERS diagnostic devices are investigated in‐depth. First, the intriguing prospect of point‐of‐care diagnostics is briefly described, followed by an introduction to the cutting‐edge SERS technique. Then, the focus is moved from conventional rigid substrate‐based SERS to the emerging flexible SERS technique. The main part of this report highlights the recent three categories of flexible SERS substrates, including actively tunable SERS, swab‐sampling strategy, and the in situ SERS detection approach. Furthermore, other promising means of flexible SERS are also introduced. The flexible SERS substrates with low‐cost, batch‐fabrication, and easy‐to‐operate characteristics can be integrated into portable Raman spectroscopes for point‐of‐care diagnostics, which are conceivable to penetrate global markets and households as next‐generation wearable sensors in the near future.