We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Atomic Force Microscopy (AFM) nanomechanical characterization of micro- and nanoplastics to support environmental investigations in groundwater
Summary
Researchers developed a new microscopy-based method using Atomic Force Microscopy (AFM) to detect and characterize micro- and nanoplastics as small as a few nanometers, finding that microplastics collected from groundwater were rougher and more aggregated than lab-aged particles — meaning they likely carry more adsorbed pollutants into drinking water sources.
Micro and nanoplastic (MNP) pollution is a severe environmental issue, posing potential risks to environmental and human health due to the intrinsic toxicity of plastic particles and their capacity to adsorb other pollutants. The diffusion of plastic debris affects all the environmental domains, including groundwater which was erroneously believed to be protected by the porous structure of the soil. Advanced spectroscopic techniques can detect the polymer type and quantify the number of MNP particles but are affected by large uncertainties in case of particles smaller than 10 μm in size and MNP heteroaggregates. To advance in the morphological and mechanical characterization of MNPs, a new protocol based on multifrequency Atomic Force Microscopy (AFM) is proposed with the support of the custom open software “MultiFreq AFMSuite”. Reconstituted MNP samples in pristine and aged conditions are used to fine-tune the methodology. Multifrequency AFM allows the detection of MNPs up to the nanometric scale based on elastic modulus assessments. The proposed technique also provides an in-depth analysis of the MNP surface roughness and the morphological characterization of particle aggregates. MNP particles from groundwater samples result in aggregates with a roughness of one to two orders of magnitude higher than the plastic particles aged in the laboratory, suggesting a higher adsorption capacity towards pollutants or other natural compounds. The application of the proposed method can facilitate the characterization of micro-and nanoplastics in groundwater, a resource characterized by large uncertainties in hydrodynamics and pollutant transport. • Multifrequency AFM distinguishes pristine and aged MNPs via the elastic modulus. • The technique provides invaluable data on MNP morphology and roughness. • MNPs in groundwater samples are successfully detected via the multifrequency AFM. • Collected groundwater samples have MNP aggregates of aged plastic fragments.