Rapid Detection of Nanoplastic Contamination in Plastic Labware by Dynamic Light Scattering Highlights Variations in Experimental Precision

Nanoplastics (NPs) are emerging contaminants of environmental concern, raising significant alarms due to their prevalence and potential health risks. Unlike larger microplastics, NPs are challenging to detect due to their nanodimensions and the reliance on labor-intensive methods such as nanoparticle tracking analysis (NTA) or scanning electron microscopy (SEM). This underscores the urgent need for rapid and accessible detection methods. To address these challenges, we employed dynamic light scattering (DLS), a widely used technique for measuring nanoparticle sizes, to rapidly quantify NP concentrations and sizes. Using DLS, we demonstrated the prevalence of NPs originating from laboratory-based plastic consumables such as microcentrifuge tubes, cryovials, and Petri dishes. Notably, routine actions, including pipet-tip scraping against plastic labware during sample handling, can introduce NPs into solutions. Moreover, physical or chemical procedures, especially sonication and liquid nitrogen treatment, further exacerbate the NP release. This interfered with experimental outcomes, including skewing of DNA and iron nanoparticle concentrations. Our material analysis revealed that the NPs were made of polystyrene and polypropylene, which correlated to manufacturers' product details. Hence, our study highlights an under-recognized NP source that compromises research integrity while contributing to global NP pollution, thus emphasizing the need for sustainable laboratory practices and robust contamination control.