Layered self-assembly CuS electrochemical sensor for methanogenic archaea detection via co-enzyme identification

An electrochemical sensor for rapid and sensitive detection of methanogenic archaea has been developed through coenzyme M identification. • Synthesis of layered self-assembled CuS nanostructures with multiple hierarchical levels by simply adjusting the molecular weight of structural directing agents. • In situ techniques have revealed detailed information about the oxidation process of coenzyme M on the surface of CuS. Atmospheric greenhouse gas methane (CH 4 ) emission in lakes, strongly related to an anaerobic process mediated by methanogenic archaea, significantly influences carbon cycling and ecosystem stability. A real time monitoring of methanogenic abundance is essential for predicting climate change dynamics and evaluating ecosystem health. The detection of archaea characteristic coenzyme is an effective method for quantifying microbial populations. In this study, we synthesized layered self-assembly copper sulfide nanostructures (nanostar) with multiple hierarchical and rich active sites for the electrochemical identification of 2-mercaptoethanesulfonate (coenzyme M), a unique biomarker participating the final step of CH 4 production during methanogenic archaea's metabolism. The constructed CuS electrochemical sensor enables quantitative detection of methanogenic archaea through catalytic oxidation of coenzymes. In situ infrared spectroscopy and time-dependent Raman spectroscopy reveal detailed insights into the oxidation process of coenzyme M on the CuS surface. The peak current of the CuS electrochemical sensor exhibits a good linear relationship with the concentration of coenzyme M, demonstrating excellent resistance to interference and stability. Furthermore, a linear correlation was established between coenzyme M (Co M) concentration and methanogenic abundance. The developed CuS biosensor enabled rapid quantification of methanogens within a range of 10 3 –10 8  CFU/mL, and realized the detection of methanogenic archaea in the bottom water samples of Donghu lake as 2*10 7  CFU/mL. This work provides a scientific foundation for lake ecosystem assessments and global carbon cycle modeling. Download: Download high-res image (112KB) Download: Download full-size image