Summary of the core size, hydrodynamic size and surface charge for each composite.

MNP@lignin	Diametera (nm)	Hydrodynamic diameterb (nm)	PDI	ζ-potential (mV)
AuNP@alkali	15 ± 7	39	0.42	−26.9
AuNP@ZHL	25 ± 8	39	0.27	−54.4
AuNP@AL	12 ± 4	21	0.65	−50.2
AgNP@alkali	8 ± 4c	65	0.52	−44.3
AgNP@ZHL	13 ± 8	52	0.28	−51.1
AgNP@AL	13 ± 6	100	0.67	−57.8

^aFrom analyses of the TEM images.

^bFrom DLS analysis.

^cOnly small particles were measured and considered. PDI: polydispersity index scaled between 0 and 1. Values higher than 0.7 indicate highly-polydisperse materials.³⁵