Monitoring marine life helps scientists track ecosystem health, improve conservation, and manage fisheries. A promising approach is environmental DNA (eDNA), which refers to trace genetic material naturally released into the water by organisms, such as skin cells, mucus and excreta. By analysing eDNA in water samples, scientists can determine which species are present in a given body of water without the need to physically capture or observe the organisms. This method is of great significance for monitoring marine ecosystems and conserving biodiversity. In practical applications, however, DNA concentrations in seawater are extremely low, making it difficult for traditional membranes to capture it effectively.
A research team led by Professor Kenneth Leung Mei-yee, CityUHK’s Vice-President (Research) and Director of the State Key Laboratory of Marine Environmental Health (SKLMEH) under the College of Science (CSCI), in collaboration with researchers from several other universities, has successfully developed a novel functionalised membrane that significantly improves the efficiency of collecting and detecting marine organisms’ eDNA, providing a more sensitive and reliable technical tool for monitoring marine biodiversity.
Professor Zeng Zhiyuan from the Department of Materials Science and Engineering and the SKLMEH is also a team member. The study, titled “A tailored MoS₂ membrane with strong DNA-binding capability enhances aquatic biota detection through environmental DNA metabarcoding”, was published in the leading international journal National Science Review.
The research team coated the surface of a common membrane with an ultra-thin layer of 2D material molybdenum disulphide (MoS₂), enabling the membrane to capture DNA in water more effectively. Experimental results show that this novel membrane significantly improves the detection sensitivity of fish eDNA in both laboratory and field tests.
In controlled experiments, the researchers successfully used the membrane to accurately identify a variety of tropical coral reef fish, including Acanthurus dussumieri, Chrysiptera cyanea, Dascyllus trimaculatus, Microcanthus strigatus, and Paracanthurus hepatus.
For field testing, the research team conducted on-site sampling tests at the Hoi Ha Wan Marine Park. The results showed that the new filter membrane could detect more fish species, including anchovies, flathead gray mullet and carangid fish, without affecting the overall assessment of the fish community, demonstrating its potential for applications in practical marine monitoring.
“The membrane is simple to prepare and cost-effective, and can be directly integrated into existing water sampling filtration processes. It is expected to find future applications in marine conservation, ecological surveys and long-term environmental monitoring, and is particularly suitable for use in marine areas rich in biological resources but difficult to survey,” noted Professor Leung.
He added that the Ministry of Ecology and Environment is currently promoting the use of eDNA technology in biodiversity surveys, and that the research team’s innovative technology will support and drive its development.
The corresponding authors of this study include Professor Leung; Professor Zeng; Professor Huang Bolong from the Department of Chemistry at CityUHK; and Professor Qiu Jianwen from the Department of Biology at Hong Kong Baptist University.
This article originated from CityUHK News Centre.