Fig. 2
From: Using Positively Charged Magnetic Nanoparticles to Capture Bacteria at Ultralow Concentration

Characterization of the nanoparticles. a Transmission electronic microscopy (TEM) image of positively charged nanoparticles (NP+) and negatively charged nanoparticles (NP−). b Dynamic light scattering size and distribution of NPs. c Zeta potential distributions of NPs