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Multidentate Poly(ethylene glycol) Ligands Provide Colloidal Stability to Semiconductor and Metallic Nanocrystals in Extreme Conditions
被引:179
作者:
Stewart, Michael H.
[1
]
Susumu, Kimihiro
[1
]
Mei, Bing C.
[1
]
Medintz, Igor L.
[2
]
Delehanty, James B.
[2
]
Blanco-Canosa, Juan B.
[3
,4
,5
]
Dawson, Philip E.
[3
,4
,5
]
Mattoussi, Hedi
[1
]
机构:
[1] USN, Res Lab, Div Opt Sci, Washington, DC 20375 USA
[2] USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA
[3] Scripps Res Inst, Dept Cell Biol, La Jolla, CA 92037 USA
[4] Scripps Res Inst, Dept Chem, La Jolla, CA 92037 USA
[5] Scripps Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA
关键词:
LOCALIZATION SIGNAL PEPTIDE;
QUANTUM DOTS;
GOLD NANOPARTICLES;
CELLS;
ACID;
DNA;
D O I:
10.1021/ja102898d
中图分类号:
O6 [化学];
学科分类号:
0703 ;
摘要:
We present the design and synthesis of a new set of poly(ethylene glycol) (PEG)-based ligands appended with multidentate anchoring groups and test their ability to provide colloidal stability to semiconductor quantum dots (QDs) and gold nanoparticles (AuNPs) in extreme buffer conditions. The ligands are made of a PEG segment appended with two thioctic acid (TA) or two dihydrolipoic acid (DHLA) anchoring groups, bis(TA)-PEG-OCH3 or bis(DHLA)-PEG-OCH3. The synthesis utilizes Michael addition to create a branch point at the end of a PEG chain combined with carbodiimide-coupling to attach two TA groups per PEG chain. Dispersions of CdSe-ZnS core-shell QDs and AuNPs with remarkable long-term colloidal stability at pHs ranging from 1.1 to 13.9 and in the presence of 2 M NaCl have been prepared and tested using these ligands. AuNPs with strong resistance to competition from dithiothreitol (as high as 1.5 M) have also been prepared. This opens up possibilities for using them as stable probes in a variety of bio-related studies where resistance to degradation at extreme pHs, at high electrolyte concentration, and in thiol-rich environments is highly desirable. The improved colloidal stability of nanocrystals afforded by the tetradentate ligands was further demonstrated via the assembly of stable QD-nuclear localization signal peptide bioconjugates that promoted intracellular uptake.
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页码:9804 / 9813
页数:10
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