Molecular bridging agent and preparation method and application thereof in Raman probe

The invention relates to a molecular bridging agent and a preparation method and an application thereof in a Raman probe. The molecular bridging agent has a chemical name of bisacetic acid-4-ethinyl thiophenol ester, and has the following structural formula defined in the specification. The bisacetic acid-4-ethinyl thiophenol ester is used as a labelled molecule for preparation of the Raman probe. Firstly, thioesters at two ends of the bisacetic acid-4-ethinyl thiophenol ester are hydrolyzed into sulfydryl (SH), the polarity is allowed to be increased, the product tends to hydrophilicity, interaction based on SH metal nanoparticles is achieved, Au or Ag nanoparticles in an aqueous phase are continuously enriched at an interface to form an assembly body, so as to form a film of the Au or Ag nanoparticles acting with the bisacetic acid-4-ethinyl thiophenol ester.