Surface-enhanced Raman Scattering on 2D Nanomaterials: Recent Developments and Applications†

Surface enhanced Raman spectroscopy (SERS) has emerged as a highly powerful and sensitive tool for molecular analysis. Of the various factors that affect SERS performance, substrate material is the most critical. Since first observed in 1974, noble metals have been the most common substrates for SERS. However, their increasing defects including low selectivity, weak uniformity, and poor stability are all obstacles to these noble metal-based SERS substrates. Recently, due to the unique layer-dependent optical properties and a very large surface-to-volume ratio, two-dimensional (2D) nanomaterials are found to be promising candidates to overcome the shortcomings of a conventional metallic SERS substrate. Herein, we concentrate on the latest development and applications of SERS-active 2D nanomaterials in our group as well as in other related research studies. The enhancement mechanism of the SERS effect and the development of various SERS-active 2D nanomaterials have been discussed in detail. Eventually, the latest development in 2D nanomaterial-SERS-based analytical applications from trace detection of small organic pollutants and macromolecular biomarkers to in-situ cytosensing and in-situ theranostic analysis is introduced.