Effective protection strategy of Surface-enhanced Raman scattering substrate in deep-sea cold seep in-situ detection

Complex environments often have irreversible effects on Surface-enhanced Raman scattering (SERS) substrates, so it is very important to design protection devices reasonably. In this paper, a simple and effective SERS substrate protection scheme was proposed. The SERS substrate was assembled on the ROV (Remote-operation Vehicle) “Faxian” and deployed in a cold seep biocenose area. The protection device was crucial for the successful application of the SERS substrate, which effectively adsorbed biological organic molecules such as amino acids and β-carotene. However, the effective detection time for low-concentration biomolecules was short (< 8 min with protection, nearly 0 without), primarily due to high inorganic salt concentrations at the vents. This study highlights the limitation of conventional SERS substrates as single-use sensors in deep-sea in-situ detection. Future designs of in-situ SERS probes should focus on substrate replacement and protection to enable multi-point detection in extreme.