2.3.5. Particle charge measurement
The electrical charge (ζ-potential) of the different systems was
measured using a particle electrophoresis instrument (Zetasizer Nano
ZA series, Malvern Instruments Ltd. Worcestershire, UK). Samples
were diluted 10- to 20-fold using 0.01 M phosphate buffer (adjusted
to same pH as the samples) prior to analysis to prevent particle interaction
effects.