Direct monitoring of the enzymatically sequestering and degrading of PET microplastics using hyperspectral Raman microscopy

Abstract

Microplastics are commonly referred to as tiny plastic fragments polluting our environment, although their nanometric forms have also been found in our drinking water supplies and many living systems. Their removal is relevant for preserving our health and sustainability and is being pursued according to many different strategies, including filtration through selective porous materials or agglomeration using flocculant agents. An alternative nanotechnological approach described in this paper deals with the capture and degradation of micro and nanoplastics by enzyme-immobilized magnetic nanoparticles. Magnetic nanoparticles (Fe₃O₄) were functionalized with polydopamine (PDA) and Lipase enzyme straightforwardly to generate agents capable of removing and degrading µPET from an aqueous solution. In addition to synthesizing and characterizing the Fe3O4@PDA-Lipase nanoparticles and performing the µPET degradation, the novelty encompassed in this work is the successful use of confocal Raman microscopy to monitor the process, in real-time, through in situ hyperspectral images.