Two-photon absorbing nanocrystal sensors for ratiometric detection of oxygen.
Two nanocrystal-osmium(II) polypyridyl (NC-Os(II)PP) conjugates have been designed to detect oxygen in biological environments. Polypyridines appended with a single free amine were linked with facility to a carboxylic acid functionality of a semiconductor NC overlayer to afford a biologically stable amide bond. The Os(II)PP complexes possess broad absorptions that extend into the red spectral region; this absorption feature makes them desirable acceptors of energy from NC donors. Fluorescence resonance energy transfer (FRET) from the NC to the Os(II)PP causes an enhanced Os(II)PP emission with a concomitant quenching of the NC emission. Owing to the large two-photon absorption cross-section of the NCs, FRET from the NC to the Os(II)PP can be established under two-photon excitation conditions. In this way, two-photon processes of metal polypyridyl complexes can be exploited for sensing. The emission of the NC is insensitive to oxygen, even at 1 atm, whereas excited states of both osmium complexes are quenched in the presence of oxygen. The NC emission may thus be used as an internal reference to correct for fluctuations in the photoluminescence intensity signal. These properties taken together establish NC-Os(II)PP conjugates as competent ratiometric, two-photon oxygen sensors for application in biological microenvironments.
McLaurin
Emily J
EJ
Department of Chemistry, 77 Massachusetts Avenue, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
Greytak
Andrew B
AB
Bawendi
Moungi G
MG
Nocera
Daniel G
DG
D031541:Fluorescence Resonance Energy Transfer; D053758:Nanoparticles / Q000737:chemistry*; D009992:Osmium / Q000737:chemistry; D010100:Oxygen / Q000032:analysis*; D017785:Photons; D011725:Pyridines / Q000737:chemistry
D011725:Pyridines; D009992:Osmium; D010100:Oxygen
Nat Biotechnol. 2003 Nov;21(11):1369-77
14595365
Chemphyschem. 2008 Aug 25;9(12):1673-9
18663708
Angew Chem Int Ed Engl. 2009;48(15):2741-5
19253320
Science. 2003 May 30;300(5624):1434-6
12775841
Nat Methods. 2005 Dec;2(12):932-40
16299478
Science. 2005 Jan 7;307(5706):58-62
15637262
Photochem Photobiol. 2002 Apr;75(4):327-34
12003120
Nat Mater. 2005 Nov;4(11):826-31
16379073
J Am Chem Soc. 2005 May 11;127(18):6744-51
15869297
J Photochem Photobiol A Chem. 2008;198(1):75-84
19030124
Curr Opin Biotechnol. 2002 Feb;13(1):40-6
11849956
J Am Chem Soc. 2006 Mar 1;128(8):2526-7
16492023
Small. 2006 Nov;2(11):1308-13
17192978
Bioconjug Chem. 2005 Nov-Dec;16(6):1488-94
16287246
Science. 2005 Jan 28;307(5709):538-44
15681376
Cancer Res. 1989 Dec 1;49(23):6449-65
2684393
Anal Chem. 2001 Sep 1;73(17):4124-33
11569801
Nat Mater. 2006 Jul;5(7):581-9
16799548
J Am Chem Soc. 2004 Jan 14;126(1):301-10
14709096
J Biol Chem. 1987 Apr 25;262(12):5476-82
3571219
Anal Chem. 2000 Aug 1;72(15):3468-75
10952529
J Am Chem Soc. 2005 Aug 24;127(33):11851-62
16104764
Nat Biotechnol. 2004 Jan;22(1):47-52
14704706
J Am Chem Soc. 2006 Oct 18;128(41):13320-1
17031920
J Phys Chem B. 2004 May 20;108(20):6315-21
18950117
Anal Biochem. 2002 Nov 15;310(2):191-8
12423638
J Am Chem Soc. 2008 Jan 30;130(4):1274-84
18177042
Chem Soc Rev. 2007 Apr;36(4):579-91
17387407
Nat Biotechnol. 2003 Jan;21(1):41-6
12459735
J Phys Chem A. 2007 Aug 2;111(30):6977-90
17608457
Nat Med. 1997 Feb;3(2):177-82
9018236
Acc Chem Res. 2006 Jun;39(6):383-93
16784216
Annu Rev Phys Chem. 1996;47:555-606
8930102
Anal Chem. 2004 May 1;76(9):2498-505
15117189
Nat Mater. 2005 Jun;4(6):435-46
15928695