Environmental DNA (eDNA) monitoring is a simple and effective method for studying marine life without directly observing or capturing organisms. Marine organisms constantly release tiny amounts of genetic material into seawater through skin cells, mucus, waste, and reproductive activities. This genetic material, known as environmental DNA, contains species-specific information and can remain in seawater for a short period of time. In eDNA-based monitoring, seawater is collected and filtered to capture DNA fragments. The DNA is then extracted from the filter and analyzed using molecular techniques to identify which species are present. By comparing the DNA sequences with known databases, scientists can determine the biodiversity of a marine area.
However, this technique suffers from low capture efficiency, particularly in areas with low DNA concentrations.
To overcome the above challenge, Prof. Leung and his team developed an developed a new eDNA sampling membrane by coating a conventional mixed cellulose ester (MCE) filter with single-layer molybdenum disulfide (MoS 2 ) nanosheets. This two-dimensional nanomaterial provides abundant adsorption sites and enables preferential interactions with DNA bases through van der Waals forces, significantly improving the capture of trace eDNA from large volumes of seawater.
In controlled experiments, the researchers successfully used the membrane to accurately identify multiple tropical coral reef fish species, including the blue tang (Paracanthurus hepatus), Dussumier’s surgeonfish (Acanthurus dussumieri), blue damselfish (Chrysiptera cyanea), three-spot damselfish (Dascyllus trimaculatus), and stripey (Microcanthus strigatus).
For field applications, the research team conducted on-site sampling tests at Hoi Ha Wan Marine Park in Hong Kong. The results showed that the new membrane was able to detect a greater number of fish species—such as anchovies, mullets, and carangid fishes—without altering the overall assessment of the fish community, demonstrating its strong potential for practical marine biodiversity monitoring.
The research team was led by Prof. Kenneth Mei Yee Leung , Prof. Zhiyuan Zeng , and Prof. Bolong Huang from CityU, in collaboration with Prof. Jian-wen Qiu from Hong Kong Baptist University. Their findings were published in the academic journal National Science Review , under the title " A tailored MoS 2 membrane with strong DNA binding capability enhances aquatic biota detection through environmental DNA metabarcoding ".
The first authors are Dr. Liang Mei (from Prof. Zeng’s group), Dr. Chun Ming How (from Prof. Qiu’s group), and Dr. Mingzi Sun (from Prof. Huang’s group).
The research received funding support from CityU, the Research Grants Council of Hong Kong, the Shenzhen Science and Technology Innovation Commission
National Science Review
Experimental study