The invention belongs to the field of surface enhanced
Raman scattering, and discloses a method for constructing an SERS (Surface Enhanced
Raman Scattering) substrate with high-density hot spots based on capillary force for detecting TNT (
Trinitrotoluene). The SERS hot spot is constructed on the basis of a periodic Ag-plated
silicon nanorod array, target molecules are adsorbed by utilizing a periodic Ag-plated
silicon nanorod array substrate, and then nanorods are mutually pulled together by utilizing capillary force generated by
solvent volatilization to form a cluster, so that the gap SERS hot spot is generated. The periodic Ag-plated
silicon nanorod array is based on a single-layer
polystyrene microsphere template, a silicon nanorod array is obtained in a mode of combining
reactive ion etching and
metal-assisted chemical
etching, and an Ag film is deposited in a magnetron
sputtering mode to obtain the Ag-plated silicon nanorod array. When TNT is detected, after the substrate adsorbs TNT molecules, the nanorods are pulled together directly by capillary force to generate gap SERS hot spots, so that the detection efficiency is improved. The method for constructing the hot spots based on the external stress is simple, convenient and efficient, and has higher sensitivity and reproducibility.