The Key to Detecting Nanoplastics
Sep 12, 2025News
Nanoplastics have become an increasing health concern as more research is compiled on the harm they cause in living organisms. Nanoplastics are so small that they can enter cells, tissues, and organs, and even cross the blood-brain barrier, causing toxic side effects. These nanoplastics are so small, it has proven challenging to quickly and reliably locate these particles. An important step to preventing such harmful plastics from entering the human body is finding an easy, effective, and affordable way to detect these nanoplastics in different resources before being consumed.
A team of scientists from the University of Stuttgart, Germany, and the University of Melbourne, Australia, combined efforts to create a test to efficiently find and analyze these tiny nanoplastic particles in environmental samples. All that is needed is an ordinary optical microscope and a newly developed test strip, coined the “optical sieve.” When viewed under a microscope, the optical sieve test strip reveals the nanoplastic particles through striking color changes.
The optical sieve is designed with small holes called depressions, or Mie voids, which are edged into a semiconductor substrate. The sieve can even provide Mie voids with different sizes so that only microplastics with particular sizes will collect in each hole. Depending on the microplastic’s diameter and depth, the particles which have been sieved into the different holes interact with the incident light, causing a bright color reflection which is visible through an optical microscope. Therefore, if there is a visible change in color, a microplastic is present.
With the development of this mobile test strip, water and soil can be directly tested on site. Prof. Harald Giessen, head of the 4th Physics Institute of the University of Stuttgart, provides this new information: “In the near future, we will be working toward analyzing nanoplastic concentrations directly on site. But our new method could also be used to test blood or tissue for nanoplastic particles.”
With the efficiency of this new test, hopes are high in preventing these toxic microplastics from causing further harm to humans. As stewards of the earth, it is important to detect and prevent such harmful toxins from affecting us and future generations.
To continue reading about the optical sieve, please find the resource link below.
