Recent progress on two-dimensional layered materials for surface enhanced Raman spectroscopy and their applications

Surface-enhanced Raman spectroscopy (SERS) has become an ultrasensitive technique in trace molecule detection through its unique vibrational fingerprint. However, development of a SERS platform with large enhancement factor, superior stability, and excellent reproducibility is still a grand challenge for practical applications. Recently, two-dimensional (2D) materials play an intriguing role for SERS through the use of their unique structures and properties. This review summarizes the recent progress of 2D materials-based SERS that could be complements to plasmonic SERS substrates. Based on the symmetry of the lattice structure, isotropic and anisotropic 2D materials for SERS are introduced. Particularly, various methods to improve the SERS performance are described. The sensitivity, limit of detection, and stability are discussed for 2D materials-based heterostructures as SERS platforms, including van der Waals and hybrid heterostructures. Furthermore, the applications of 2D materials-based SERS substrates in niche areas, including local strain probing, remote/in-situ chemical analysis, and fine structure characterization are summarized.