Detecting Nanoplastic Particles using Correlative Microscopy

Nowadays “microplastics” (MPs) is an already well-known term and micro-sized particles are increasinglyfound in several consumer products [1]. Moreover, effects of micro- and nanoplastics (NPs) on human healthhave been investigated and discussed [2]. In this study, the focus is pointed to MPs smaller than 1 μm, witha specific focus on particles in the scale of a couple of 100 nm, which are referred here as NPs. A correlativeapproach between scanning electron microscopy (SEM, high resolution) and Raman microscopy (chemicalidentification) was tested to meet the challenges of finding and identifying these small particles. For thispurpose standardized polystyrene (PS) beads were mixed into various environments in differentconcentrations, ranging from ideal (distilled water) to realistic (sea salt, human amniotic fluid), to proof thedetection limit of NPs with the so called RISE (Raman Imaging and Scanning Electron microscopy) system[3]. Promising results exhibit detection limits of 2·10-3 μg/L (distilled water), 20 μg/L (sea salt) and 200 μg/L(human amniotic fluid).