Ultrahigh nanoparticle stability against salt, pH, and solvent with retained surface accessibility via depletion stabilization.
For many applications, it is desirable to stabilize colloids over a wide range of buffer conditions while still retaining surface accessibility for adsorption and reaction. Commonly used charge or steric stabilization cannot achieve this goal since the former is sensitive to salt and the latter blocks the particle surface. We use depletion stabilization in the presence of high molecular weight polyethylene glycol (PEG) to stabilize a diverse range of nanomaterials, including gold nanoparticles (from 10 to 100 nm), graphene oxide, quantum dots, silica nanoparticles, and liposomes in the presence of Mg(2+) (>1.6 M), heavy metal ions, extreme pH (pH 1-13), organic solvents, and adsorbed nucleosides and drugs. At the same time, the particle surface remains accessible for adsorption of both small molecules and macromolecules. Based on this study, high loading of thiolated DNA was achieved in one step with just 2% PEG 20,000 in 2 h.
Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1.
Xu
X
Zhang
Mark R
MR
Servos
Juewen
J
Liu
D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008081:Liposomes / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D012492:Salts / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties
D008081:Liposomes; D019216:Metals, Heavy; D010087:Oxides; D012492:Salts; D012997:Solvents; D011092:Polyethylene Glycols; D006046:Gold; D012822:Silicon Dioxide; D006108:Graphite; D008274:Magnesium