A flexible surface-enhanced Raman substrates based on cellulose photonic crystal/Ag-nanoparticles composite

For surface-enhanced Raman scattering (SERS) sensing technology, it is required that the SERS substrates should obtain not only high sensitivity but also outstanding signal stability and good affinity for the target analytes. In this work we designed a cellulose photonic crystal (PhC) modified with Ag-nanoparticles, which can enhance the Raman signal through the combination of the affinity of cellulose to target analyte in organic solvents, the plasmonic responses of Ag-nanoparticles and the trapping effect of PhC on light. As a result, the concentration of p-methylthiopheno down to 10 ⁻⁶ M can be detected quantitatively. The cellulose PhC SERS substrate has the good affinity for organic solvents, which is easy to prepare and preserve, and shows promising prospect in sensor techniques.