A research team has outlined a fluorescence-based strategy designed to make microplastics and nanoplastics visible inside living organisms, potentially enabling real-time tracking of how the particles move, change and break down in biological systems.
Microplastics and nanoplastics—small fragments of plastic—have been detected across the planet, including in deep ocean waters, agricultural soils, wildlife and human tissues such as blood, liver and brain samples. Global plastic production now exceeds 460 million tons per year, and scientists estimate that millions of tons of microscopic plastic particles are released into the environment annually.
Laboratory experiments have suggested that exposure to micro- and nano-plastics may be associated with inflammation, organ damage and developmental problems. Even so, researchers say a major gap remains: it is difficult to directly observe, over time, what these particles do once they enter living organisms.
Why existing detection tools fall short
Conventional approaches used to identify microplastics in biological samples—including infrared spectroscopy and mass spectrometry—typically require destructive sample preparation, which prevents continuous observation and often yields only a single “snapshot” of what is present at a given moment. Fluorescence imaging can, in principle, enable dynamic tracking, but commonly used labeling methods can suffer from fading signals, dye leakage and reduced brightness in complex biological environments.
A “fluorescent monomer-controlled” synthesis concept
To address those limitations, researchers led by Wenhong Fan described what they call a “fluorescent monomer-controlled synthesis” strategy. Instead of coating plastic particles with fluorescent dyes, the approach incorporates light-emitting components into the polymer’s molecular structure.
The concept uses aggregation-induced emission (AIE) materials—compounds that emit more strongly when clustered—to help generate a stable signal. The researchers say the design could allow the brightness and emission color to be tuned, along with particle size and shape. Because the fluorescent components are distributed throughout the particle, the team says both intact plastics and the smaller fragments produced during degradation could remain visible, potentially enabling tracking from ingestion and internal transport through transformation and breakdown.
“Most current methods give us only a snapshot in time,” Fan said. “We can measure how many particles are present in a tissue, but we cannot directly observe how they travel, accumulate, transform, or break down inside living organisms.”
Early-stage work aimed at improving risk research
The strategy was described in the journal New Contaminants and is still undergoing experimental validation, the researchers said. They argue that, if the approach performs as intended, it could support studies of how microplastics interact with cells, tissues and organs—work that may ultimately improve ecological and health risk assessments.
“Clarifying the transport and transformation processes of microplastics inside organisms is essential for assessing their true ecological and health risks,” Fan said. “Dynamic tracking will help us move beyond simple exposure measurements toward a deeper understanding of toxicity mechanisms.”
As concern about plastic pollution grows, researchers say tools that allow closer observation of microplastics’ behavior in living systems could help inform future scientific assessments and, potentially, environmental policy discussions.
