Supplementary Information for Size Control of Highly Monodisperse Citrate-Stabilized Magnetite Nanoparticles in Aqueous Media: The Role of Cerium Cations

Representative TEM, STEM, and HRTEM images; size distributions; zeta potential and FTIR spectra; XPS survey scans and peak deconvolutions; XRD diffractograms and lattice parameter comparisons; UV–vis monitoring of the Ce–SC complex; magnetic characterization (half-magnetization curves, zero-field-cooled/field-cooled curves); and TMB colorimetric reaction kinetics and spectra (including leaching test)