Surface-enhanced Raman spectrum substrate and preparation method

The invention discloses a surface-enhanced Raman spectrum substrate and a preparation method. The surface-enhanced Raman spectrum substrate comprises chitosan nano-particles, and is characterized in that nano-gold particles are connected to the surfaces of the chitosan nano-particles through covalent bonds. A preparation method for the surface-enhanced Raman spectrum substrate comprises the step of mixing chitosan nano-particle aqueous solution with nano-gold particle aqueous solution in a volume ratio of 1 to 1, wherein the concentration of the chitosan nano-particle aqueous solution is 1-4g/L, and the concentration of the nano-gold particle aqueous solution is 1-4nmol/L. The method disclosed by the invention is simple and practicable, and does not need large-scale instrument and equipment; the prepared surface-enhanced Raman spectrum substrate is good in stability, and has an excellent Raman signal amplification effect.