Luminous Upconverted Nanoparticles as High-Sensitivity Optical Probes for Visualizing Nano- and Microplastics in
Bushra Maryam1, Yi Wang1, Xiaoran Li1
1School of Environmental Sciences and Engineering, Tianjin University, Tianjin 300072, China.
Sensors (Basel, Switzerland)
|September 19, 2025
Summary
New luminous nanoparticles visualize plastic ingestion in nematodes. Microplastics stay in the gut, while nanoplastics enter circulation, revealing distinct pollution impacts.
Area of Science:
- Environmental Science
- Toxicology
- Materials Science
Background:
- Plastic pollution, particularly microplastics and nanoplastics, poses a significant threat to soil ecosystems and food security.
- Traditional detection methods for plastic particles in organisms suffer from high background noise and autofluorescence interference.
- Understanding the biodistribution and toxicological effects of different plastic sizes in organisms is essential.
Purpose of the Study:
- To develop and utilize novel upconverted nanoparticles as sensitive probes for real-time visualization of plastic ingestion and biodistribution in *Caenorhabditis elegans*.
- To investigate the size-dependent distribution patterns and tissue penetration of polystyrene microplastics (PS-MPs) and nanoplastics (PS-NPs).
- To assess the differential toxicity of PS-MPs and PS-NPs at the organismal level.
Main Methods:
- Synthesis of luminous NaYF4:Yb3+/Er3+ upconverted nanoparticles for near-infrared-to-visible light conversion.
- Real-time microscopic imaging to visualize the ingestion and biodistribution of PS-MPs and PS-NPs in *C. elegans*.
- Quantitative fluorescence analysis to determine plastic bioavailability and tissue penetration.
- Assessment of locomotor impairments and physiological disruptions to evaluate toxicity.
Main Results:
- Upconverted nanoparticles provided high-sensitivity, real-time imaging of plastic uptake, overcoming limitations of traditional probes.
- Microscopic imaging revealed distinct distribution patterns: PS-MPs were confined to the digestive tract, while PS-NPs penetrated the intestinal wall into systemic circulation.
- Quantitative analysis showed PS-NPs had higher bioavailability and deeper tissue penetration compared to PS-MPs.
- Locomotor impairments and physiological disruptions indicated differential toxicity between PS-NPs and PS-MPs.
Conclusions:
- Upconverted nanoparticles are effective, sensitive, and non-invasive bio-imaging probes for tracking nano- and microplastics in biological systems.
- This study provides crucial insights into the size-dependent biodistribution and toxicity of plastic pollutants in *C. elegans*.
- The findings highlight the potential of upconverted nanoparticles for broader applications in environmental monitoring and toxicological studies.
