Surface-enhanced Raman spectrum detection sensor as well as preparation method and application thereof

The invention belongs to the technical field of optical sensing, and particularly relates to a surface-enhanced Raman spectrum detection sensor as well as a preparation method and application thereof. The preparation method of the sensor comprises the following steps: reducing silver nitrate on a glassy carbon fiber paper substrate by using sodium borohydride and ascorbic acid, so that silver nanoparticles are deposited on the surface of the glassy carbon fiber paper to form an SERS paper substrate; a reducing agent TCEP is used for reducing nucleic acid aptamer DNA of sulfydryl modified heavy metal ions, a modified paper-based SERS sensor is formed, an SERS paper substrate has recognition and sensing functions on the corresponding heavy metal ions and can be used for detecting the content of the heavy metal ions in milk, and the method comprises the steps that a heavy metal ion concentration standard curve is established; putting the milk sample into the heavy metal ion standard substance solution, and detec