Multispectroscopic Investigations of the Binding Interaction between Polyethylene Microplastics and Human Hemoglobin

In this investigation, different multispectroscopic analytical techniques have been used to explore the interaction between polyethylene microplastics (PE-MPs) and human hemoglobin (HHb), an oxygen carrier in the human blood circulatory system. Ultraviolet–visible absorption studies have demonstrated that HHb molecules may interact with PE-MPs, and thermal melting studies have indicated that PE-MPs have a stabilizing effect on HHb. Further circular dichroism and Fourier transform infrared spectroscopic studies have revealed the distinct changes in HHb's secondary structures caused by the formation of the HHb–PE-MP binding complex. These findings imply that PE-MPs could enter the blood circulation system of humans and may be hazardous to humans. This work explains the potential binding interaction of microplastics at the molecular level and offers insight into the intermolecular interaction between PE-MPs and HHb.