April 10, 2025 – In the field of environmental science, Ocean University of China has recently announced an exciting breakthrough. Associate Professor Shi Xiaofeng from the College of Information Science and Engineering and the Ministry of Education Engineering Research Center for Marine Physical High – end Instrumentation, collaborating with Professor Zhao Jian from the College of Environmental Science and Engineering and the Key Laboratory of Marine Environment and Ecology, Ministry of Education, has achieved significant progress in the precise manipulation, enrichment, and detection of nanoplastics in water. Their latest research findings, titled “Capturing, enriching and detecting nanoplastics in water based on optical manipulation, surface – enhanced Raman scattering and microfluidics”, have been successfully published in the internationally renowned academic journal Nature Water, marking a remarkable achievement of interdisciplinary cooperation within the university.
At present, micro – and nano – plastics have become new and highly – concerned environmental pollutants in the 21st century. Their continuous accumulation in global aquatic ecosystems is subtly but profoundly altering the ecological system. Compared with microplastics, nanoplastics, due to their stronger surface activity, water migration ability, and bio – accumulative properties, are likely to pose a more severe threat to the water environment and human health. However, due to the limitations of nanoplastics detection technology and the complex nature of natural water bodies, accurately determining the occurrence level of nanoplastics in the water environment is extremely difficult, which undoubtedly greatly hinders the environmental risk assessment and prediction of nanoplastics.
According to AsiaMB, the research team adopted an innovative approach this time. Based on the photothermal effect and surface – enhanced Raman characteristics of gold nanoparticle aggregates, they innovatively constructed an optical manipulation – surface – enhanced Raman (OM – SERS) detection system. With the help of this system and the self – developed photothermal tweezers, they successfully achieved precise and fine manipulation of nanoplastics in water samples. Moreover, considering the extremely low concentration of nanoplastics in the water environment, which makes direct detection very difficult, and the unsatisfactory recovery rate of existing enrichment methods, the research team cleverly utilized the photothermal trap generated by the OM – SERS system to efficiently enrich low – concentration (1 μg/L) nanoplastics. At the same time, they were able to simultaneously perform SERS qualitative and quantitative detection of nanoplastics in water. The team further integrated a microfluidic platform and developed a “photothermal enrichment – matrix cleaning – in – situ detection” process for nanoplastics (as shown in Figure 1). With this process, they successfully applied the OM – SERS system to the simultaneous enrichment and detection of nanoplastics in natural water bodies, and quickly obtained the occurrence levels of polystyrene, polyethylene terephthalate and other nanoplastics in samples such as river water and seawater. In addition to the unique advantage of simultaneous enrichment – detection, this newly developed OM – SERS system also has many advantages such as high detection sensitivity and small single – sample volume requirement (<7.2 mL), successfully overcoming the technical difficulties of rapid detection of nanoplastics in the water environment. This technological achievement will provide strong technical support for the detection of nanoplastics in the water environment, the study of geochemical processes, and ecological risk assessment in the future.
(Schematic diagram of the process for detecting nanoplastics based on the optical manipulation – surface – enhanced Raman spectroscopy (OM – SERS) system)
Associate Professor Shi Xiaofeng of Ocean University of China and three master’s students, Mao Tianyu (Optics), Huang Xiangmin (Optical Engineering), and Shi Hui (Optics), are the co – first authors of this paper. Professor Zhao Jian of Ocean University of China and Professor Baoshan Xing of the University of Massachusetts, USA, are the co – corresponding authors. In addition, Professor Ma Jun, Associate Professor Zhao Hang of Ocean University of China, Ph.D. student Lan Ruyi (Environmental Science), and master’s student Jiang Kaiyang (Physics) also made continuous and crucial contributions to the successful completion of this research.