Imperial College London

Prof Milo Shaffer

Faculty of Natural SciencesDepartment of Chemistry

Professor of Materials Chemistry



+44 (0)20 7594 5825m.shaffer Website




Mr John Murrell +44 (0)20 7594 2845




M221Royal College of ScienceSouth Kensington Campus






BibTex format

author = {Leo, BF and Chen, S and Kyo, Y and Herpoldt, KL and Terrill, NJ and Dunlop, IE and McPhail, D and Shaffer, MS and Schwander, S and Gow, A and Zhang, J and Chung, KF and Tetley, T and Porter, AE and Ryan, MP},
doi = {10.1021/es403377p},
journal = {Environ Sci Technol},
pages = {11232--11240},
title = {The Stability of Silver Nanoparticles in a Model of Pulmonary Surfactant.},
url = {},
volume = {47},
year = {2013}

RIS format (EndNote, RefMan)

AB - The growing use of silver nanoparticles (AgNPs) in consumer products has raised concerns about their potential impact on the environment and human health. Whether AgNPs dissolve and release Ag+ ions, or coarsen to form large aggregates, is critical in determining their potential toxicity. In this work, the stability of AgNPs in dipalmitoylphosphatidylcholine (DPPC), the major component of pulmonary surfactant, was investigated as a function of pH. Spherical, citrate-capped AgNPs with average diameters of 14 ± 1.6 nm (n=200) were prepared by a chemical bath reduction. The kinetics of Ag+ ion release was strongly pH-dependent. After 14 days of incubation in sodium perchlorate (NaClO4) or perchloric acid (HClO4) solutions, the total fraction of AgNPs dissolved varied from ~10 % at pH 3, to ~2 % at pH 5, with negligible dissolution at pH 7. A decrease in pH from 7 to 3 also promoted particle aggregation and coarsening. DPPC (100 mg.L-1) delayed the release of Ag+ ions, but did not significantly alter the total amount of Ag+ released after two weeks. In addition, DPPC improved the dispersion of the AgNPs and inhibited aggregation and coarsening. TEM images revealed that the AgNPs were coated with a DPPC layer serving as a semi-permeable layer. Hence, lung lining fluid, particularly DPPC, can modify the aggregation state and kinetics of Ag+ ion release of inhaled AgNPs in the lung. These observations have important implications for predicting the potential reactivity of AgNPs in the lung and the environment.
AU - Leo,BF
AU - Chen,S
AU - Kyo,Y
AU - Herpoldt,KL
AU - Terrill,NJ
AU - Dunlop,IE
AU - McPhail,D
AU - Shaffer,MS
AU - Schwander,S
AU - Gow,A
AU - Zhang,J
AU - Chung,KF
AU - Tetley,T
AU - Porter,AE
AU - Ryan,MP
DO - 10.1021/es403377p
EP - 11240
PY - 2013///
SP - 11232
TI - The Stability of Silver Nanoparticles in a Model of Pulmonary Surfactant.
T2 - Environ Sci Technol
UR -
UR -
VL - 47
ER -