Alkyl passivation and amphiphilic polymer coating of silicon nanocrystals for diagnostic imaging.
A method to produce biocompatible polymer-coated silicon nanocrystals for medical imaging is shown. Silica-embedded Si nanocrystals are formed by HSQ thermolysis. The nanocrystals are then liberated from the oxide and terminated with Si-H bonds by HF etching, followed by alkyl monolayer passivation by thermal hydrosilylation. The Si nanocrystals have an average diameter of 2.1 nm ± 0.6 nm and photoluminesce with a peak emission wavelength of 650 nm, which lies within the transmission window of 650-900 nm that is useful for biological imaging. The hydrophobic Si nanocrystals are then coated with an amphiphilic polymer for dispersion in aqueous media with the pH ranging between 7 and 10 and an ionic strength between 30 mM and 2 M, while maintaining a bright and stable photoluminescence and a hydrodynamic radius of only 20 nm. Fluorescence imaging of polymer-coated Si nanocrystals in biological tissue is demonstrated, showing the potential for in vivo imaging.
Hessel
Colin M
CM
Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
Rasch
Michael R
MR
Hueso
Jose L
JL
Goodfellow
Brian W
BW
Akhavan
Vahid A
VA
Puvanakrishnan
Priyaveena
P
Tunnel
James W
JW
Korgel
Brian A
BA
D000477:Alkylating Agents / Q000737:chemistry / Q000494:pharmacology; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D003952:Diagnostic Imaging / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D006900:Hydroxylation / Q000187:drug effects / Q000502:physiology; D008954:Models, Biological; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry* / Q000494:pharmacology; D014961:X-Ray Diffraction
D000477:Alkylating Agents; D020099:Coated Materials, Biocompatible; D011108:Polymers; D013501:Surface-Active Agents; D012825:Silicon
Anal Chem. 1999 Aug 1;71(15):3133-9
10450159
Nano Lett. 2004 Jan 1;4(1):11-18
28890669
Annu Rev Biomed Eng. 2005;7:55-76
16004566
Science. 2003 May 30;300(5624):1434-6
12775841
J Biomed Opt. 2009 Mar-Apr;14(2):024044
19405772
J Am Chem Soc. 2005 Dec 28;127(51):18212-21
16366574
Proc Natl Acad Sci U S A. 2005 Jul 5;102(27):9469-74
15972807
Science. 2002 Nov 29;298(5599):1759-62
12459582
J Mater Chem. 2009 Jan 1;19:4655-4672
20305738
Nanotechnology. 2007 Jan 24;18(9):095601-95601
25170189
Nat Mater. 2009 Apr;8(4):331-6
19234444
Appl Opt. 2001 Aug 20;40(24):4087-91
18360445
Chem Commun (Camb). 2006 Oct 28;(40):4160-8
17031422
Part Fibre Toxicol. 2007 Oct 19;4:10
17949501
J Am Chem Soc. 2004 Jun 2;126(21):6520-1
15161257
Biomaterials. 1998 Jan-Feb;19(1-3):45-53
9678849
Nat Biotechnol. 2001 Apr;19(4):316-7
11283581
ACS Nano. 2008 May;2(5):873-8
19206483
Nat Nanotechnol. 2008 Mar;3(3):145-50
18654486
Langmuir. 2004 May 25;20(11):4720-7
15969188
Science. 1998 Sep 25;281(5385):2016-8
9748158
J Inorg Biochem. 1998 Feb 15;69(3):177-80
9629677
Small. 2008 Mar;4(3):334-41
18273855
Nanotechnology. 2008 Jun 18;19(24):245603
21825815
J Am Chem Soc. 2009 Jan 21;131(2):809-15
19140800
Langmuir. 2005 Jun 21;21(13):6054-62
15952860
Nat Biotechnol. 2007 Oct;25(10):1165-70
17891134