Extended Data Fig. 3. Biomolecular adsorption on different commodity plastics, its charge dependency and protein aggregation at hydrophobic plastic-water interfaces.

a, Confocal fluorescence images of surface localization of charged biomolecules including proteins and DNA at different hydrophobic plastic-water interfaces. Scale bar: 50 µm. b-c, Simultaneous imaging of the different surface partition of positively charged and negatively charged proteins. b, Simultaneous confocal fluorescence imaging of surface partition of negatively charged R-PE (left) and positively charged WGA-Alexa 647 conjugate (right). WGA conjugated with Alexa Fluor 647 was imaged in the far-red channel, excited by an LD laser (635 nm) with fluorescence collected between 655–755 nm. R-phycoerythrin (R-PE) is imaged in the red channel, excited by a HeNe(G) laser (543 nm) with emission collected between 560–620 nm. Simultaneous imaging of the two channels reveals the different partition pattern of proteins of different charges on plastic surfaces. c, Line profile of the fluorescence intensity at the corresponding dash line in panel b. d, Protein aggregation at plastic-water interface. Confocal images of the fluorogenic Thioflavin T on the surface of microplastics are shown in pair with the corresponding brightfield images of plastic particles in PBS. Scale bar: 50 µm.