The end of a project, but the start of many new ideas

Nanosilver particle detection via a fast test was the topic of the CheckNano project. As nanoparticles are used in many applications to improve products, it is crucial to control the size of the particles in use. It was demonstrated that silver nanoparticles of dimensions of a few tens of nanometers penetrate cell membranes and lead to cell death.

Several methods have been tested within the project period, bringing in the expertise of all partners and their facilities to improve and validate existing methods. Three years brought the project team closer to the limits of many of these methods, and a fast test has been developed. Preselection of the particles via filtering and a subsequent exact optical sizing and fine filtration builds the basis of this test.

In the meantime, it has been realized that plastic pollution is becoming a serious issue for our environment and is thus in society’s focus. It would be naïve to think that the plastic we release each day in our environment simply disappears. Therefore one of the goals of the final conference was to bring together also experts in plastic particle measurements and to evaluate possible extensions of the nanosilver particle detection methods.

Gunnar Gerdts pointed out that microplastics prevails in snow from the Alps to the Arctic. In his opinion, the main challenge for observations is the sample preparation that should not introduce any bias to the data. As the EU requires reporting of the environmental status, more emphasis is needed on the applied methods, and experts need to be involved.

We know nothing about nanoplastics

Elvis Genbo Xu emphasized that the number of scientific publications that address microplastics shows a steep increase in recent years. Microplastics, however, makes up only about 1% of the total plastics in our oceans, and we know little to nothing about nanoplastics. Sadly it is expected that by 2050 there will be more plastic in the oceans by weight than fish. Most of these particles come from textiles and car tyres. Also, the masks that we frequently use consist of 3 layers with inbuild plastic fibres, contributing an extra 129 billion each month worldwide. We don’t know the environmental relevance.

Nicole Posth addressed the processes that lead to the degradation of plastics, the formation of microplastics, the various uptakes of the particles in the sediment, and their chemical effects. Size matters and micro- nanoplastics might form aggregates within and become part of a cell-mineral matrix. Their water column exposures showed quick colonization by diatoms on both polyethylene and polystyrene. It is essential to find out about the processes that form the minerals. Many plastics end up in the sediment and alter geochemistry.

Emil Højlund Nielsen from CPHNANO introduced a novel technique to detect nanoparticles. This technique is suitable for field measurements and comes at a low price. It combines UV-VIS spectrophotometry with disposable nanocuvettes. These nanocuvettes have an inbuild photonic crystal that acts as an optical filter. They are especially suitable for measuring in the range between micro and nano.
By these talks, the different aspects of plastic nanoparticle detection and impact got nicely covered and opened up for discussions about future projects.