The invention discloses a preparation method for a cubic nanogold SERS probe used for TNT detection. The preparation method comprises
seed crystal gold preparation, further growth and the
functional modification and the
self assembling of a
silicon wafer. The preparation process of the preparation method comprises the following steps that: firstly, preparing
seed crystal gold, and enabling the
seed crystal gold to further grow; secondly, through a seed growth mechanism, strictly controlling the growth environment of the seed
crystal gold to enable the seed
crystal gold to grow into a cubic structure; thirdly, modifying sulfydryl on a polished 1*1cm<2>
silicon wafer to enable a gold particle
monolayer to be assembled to the surface of the
silicon wafer on the own; and finally, modifying thesurface of the silicon wafer with
electron-rich amino, realizing the selective recognition of the TNT further through a
static electricity mutual function with three
electron deficiency nitryls in aTNT target molecule, and utilizing a local area
plasma resonance field on the surface of the nanogold to amplify and enhance the conventional Raman
signal of the TNT molecule so as to realize the trace detection of the TNT, wherein a
detection limit is 10<-9>mol.L<-1>. The preparation method has the advantages of being simple in preparation, convenient in operation, low in cost, good in selectivity and high in sensitivity.