Solution Stability of Biocompatible Coatings for Nanoparticles

  • Nahla Rizk

Student thesis: Master's Thesis


The increasing use of nanoparticles (NPs) in biological systems such as in vitro assays, in vivo imaging, cancer therapy, and drug delivery, requires significant understanding of NP stability. The protective effect of biocompatible coatings against aggregation and sedimentation is essential to understand and control the biological interactions of functionalized nanoparticles. We present results on the stability of four types of coated gold nanoparticles, which are CIT-AuNPs, BSA-AuNPs, PVP, AuNPs, and PEG-AuNPs, in different environmental conditions. These stable colloidal suspensions are synthesized and their stability is tested by mixing with different destabilizing chemicals at various concentrations, mimicking four different destabilizing environments: acidic (HCl), basic (NaOH), oxidative acidic (HNO3), and high ionic strength (NaCl). AuNPs were characterized by ultraviolet visible spectroscopy (UV-Vis), dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Regions of stability were quantified for each destabilizing environment based on mixing concentrations of both the destabilizer and the colloidal suapension. Our results enable the pre-application analysis of complex interactions between the AuNPs surface with its environment. This screening method can be extended to other colloidal suspensions with various coatings to establish an understanding of their stability conditions for better efficiency in biological research and applications.
Date of AwardMar 2020
Original languageAmerican English


  • Electrosteric Stabilization; Colloidal Stability; Gold Nanoparticles
  • Turkevitch Method.

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