Facile synthesis of Ag-niobium ditelluride nanocomposites for the molecular fingerprint analysis of muscle tissues

The surface-enhanced Raman scattering (SERS) technique has attracted increasing attention in biomedicine due to the capability of providing the molecular fingerprint information of biosamples. Two-dimensional (2D) metal nanohybrids have proven to be efficient SERS substrates for bioanalysis due to the cooperative Raman enhancement mechanism. Herein, a facile strategy for the fabrication of a novel transition metal telluride-based 2D-metal SERS substrate is proposed. Ag-niobium ditelluride (NbTe2) nanocomposites are synthesized through in situ reduction of Ag nanoparticles on NbTe2 nanosheets (NSs). The excellent SERS performance of Ag–NbTe2 NSs probably originates from the coupling effect of enhanced electromagnetic field distribution around the plasmonic nanostructure (hot spots) and the charge transfer caused by the semiconductor material after numerical simulations. Using Ag–NbTe2 NSs as an ultrasensitive SERS probe, the molecular components of three types of muscle tissues are clearly identified. An effective classification of skeletal, cardiac and smooth muscles is also realized according to their SERS data plus principal component analysis. In addition, the monitoring of the skeletal muscle stretching process is achieved by the Ag–NbTe2 NS-based SERS analysis, which represents a powerful tool for molecular exercise physiology.