The phenomenon of chemically synthesized life in extreme deep-sea environment is an international research hotspot in deep-sea science and life science. However, due to the extremely low concentration of organic macromolecules such as extracellular metabolites synthesized by deep-sea chemicals and the complex surrounding environment, there is no in-situ detection technology so far.

Recently, a research team led by Prof. ZHANG Xin from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), with researchers from the Institute of Physics, has developed a new type of Raman scattering insertion probe (RiP-SERS) to detect deep sea biological macromolecules.

The probe was based on the early developed nanomaterial, which breaks through the Surface Enhanced Raman spectroscopy (SERS) detection technology in the deep-sea environment resistant to high pressure, low temperature, high salt and turbid fluid.

The study was published in Applied Surface Science on Feb. 26.

The researchers designed this new type of RiP-SERS and adjusted the SERS substrate at the Raman laser-focusing position (the distance was 3 ± 0.5 mm). At the cold seep vents of the Formosa Ridge in the South China Sea, they used ROV Faxian equipped with RiP-SERS system to achieve pressure resistance test for the SERS substrate.

What's more, they used RiP-SERS to obtain Raman spectral data of bioinformation molecules in the seawater-sediment interface of Haima cold seep vents, and found that the marine-biome interface was rich in acetyl-CoA, β-carotene, and four amino acids. The success of this experiment adds a new method for future deep-sea biomolecular detection.

"The SERS substrate can be used for macromolecule detection in complex industrial systems because it can withstand a complex deep-sea cold-seep environment (pressure, salinity, pH, and metal-salt presence)," said WANG Siyu, first author of the study.

"This is another breakthrough after the team developed RiP-Cs, RiP-Pw, RiP-Hv and RiP-Gh probes," said Prof. ZHANG, corresponding author of the study.