Abstract

Luminescent Au nanoparticles were synthesized in a modified Brust method (average diameters of metal core = 1.6 nm). The fluorescence images were measured using scanning confocal microscopy and validated as compared with organic fluorophores. The metal particles were functionalized with succinimidyl ester terminated ligands and bound as fluorophores on surface-aminated silica beads to mimic labeling of biological functionalities. The labeled silica beads were shown to display bright signals and good photostability. Our results indicate that the luminescent metal nanoparticles can be employed as the probes to label the biological functionalities in developing molecule imaging agents.

© 2007 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
    [CrossRef]
  2. D. J. Hawrysz and E. M. Sevick-Muraca, "Developments toward diagnostic breast cancer imaging using near-infrared optical measurements and fluorescent contrast agents," Neoplasia 2, 388-417(2000).
    [CrossRef]
  3. J.-P. Knemeyer, D.-P. Herten, and M. Sauer, "Detection and identification of single molecules in living cells using spectrally resolved fluorescence lifetime imaging microscopy," Anal. Chem. 75, 2147-2153 (2003).
    [CrossRef] [PubMed]
  4. J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
    [CrossRef] [PubMed]
  5. V. Ntziachristos and B. Chance, "Breast imaging technology: Probing physiology and molecular function using optical imaging - applications to breast cancer," Breast Cancer Res. 3, 41-46 (2001).
    [CrossRef] [PubMed]
  6. P. V. Kamat, "Photophysical, photochemical and photocatalytic aspects of metal nanoparticles," J. Phys. Chem. B 106, 7729 (2002).
    [CrossRef]
  7. M.-C. Daniel and D. Astruc, "Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology," Chem. Rev. 104, 293-346 (2004).
    [CrossRef] [PubMed]
  8. N. L. Rosi, and C. A. Mirkin, "Nanostructures in biodiagnostics," Chem. Rev. 105, 1547-1562 (2005).
    [CrossRef] [PubMed]
  9. R. M. Penner, "Hybrid electrochemical/chemical synthesis of quantum dots," Acc. Chem. Res. 33, 78-86 (2003).
    [CrossRef]
  10. G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
    [CrossRef]
  11. C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
    [CrossRef]
  12. M. A. El-Sayed, "Small is different: shape-, size-, and composition-dependent properties of some colloidal semiconductor nanocrystals," Acc. Chem. Res. 37, 326-333 (2004).
    [CrossRef] [PubMed]
  13. J. R. Reimers and N. S. Hush, "The need for quantum-mechanical treatment of capacitance and related properties of nanoelectrodes," J. Phys. Chem. B 105, 8979-8988 (2001).
    [CrossRef]
  14. G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
    [CrossRef] [PubMed]
  15. J. Zheng, C. Zhang, and R. M. Dickson, "Highly fluorescent, water-soluble, size-tunable gold quantum dots," Phys. Rev. Lett. 93, 077402 (2004).
    [CrossRef] [PubMed]
  16. T. Huang, and R. W. Murray, "Visible luminescence of water-soluble monolayer-protected gold clusters," J. Phys. Chem. B 105, 12498-12502 (2001).
    [CrossRef]
  17. T. P. Bigioni, R. L. Whetten, and O. Dag, "Near-infrared luminescence from small gold nanocrystals," J. Phys. Chem. B 104, 6983-6986 (2000).
    [CrossRef]
  18. S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
    [CrossRef]
  19. Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
    [CrossRef] [PubMed]
  20. G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
    [CrossRef] [PubMed]
  21. J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
    [CrossRef]
  22. J. Zhang and J. R. Lakowicz, "Enhanced luminescence of phenyl-phenanthridine dye on aggregated small silver nanoparticles," J. Phys. Chem. B. 109, 8701-8706 (2005).
    [CrossRef]
  23. R. S. Ingram, M. J. Hostetler, and R. W. Murray, "Poly-hetero--functionalized alkanethiolate-stabilized gold cluster compounds," J. Am. Chem. Soc. 119, 9175-9178 (1997).
    [CrossRef]
  24. W. Stöber, A. Fink, E. Bohn, "A novel method for synthesis of silica nanoparticles," J. Colloid Interface Sci. 26, 62-68 (1968).
  25. J. Zhang, Y. Fu, and J. R. Lakowicz, "Dye-labeled silver nanoshell-bright particle," J. Phys. Chem. B. 110, 8986-8991 (2006).
    [CrossRef] [PubMed]
  26. J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
    [CrossRef] [PubMed]
  27. T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
    [CrossRef] [PubMed]

2007 (2)

J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
[CrossRef] [PubMed]

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

2006 (2)

J. Zhang, Y. Fu, and J. R. Lakowicz, "Dye-labeled silver nanoshell-bright particle," J. Phys. Chem. B. 110, 8986-8991 (2006).
[CrossRef] [PubMed]

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

2005 (3)

N. L. Rosi, and C. A. Mirkin, "Nanostructures in biodiagnostics," Chem. Rev. 105, 1547-1562 (2005).
[CrossRef] [PubMed]

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

J. Zhang and J. R. Lakowicz, "Enhanced luminescence of phenyl-phenanthridine dye on aggregated small silver nanoparticles," J. Phys. Chem. B. 109, 8701-8706 (2005).
[CrossRef]

2004 (5)

J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
[CrossRef]

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

M.-C. Daniel and D. Astruc, "Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology," Chem. Rev. 104, 293-346 (2004).
[CrossRef] [PubMed]

J. Zheng, C. Zhang, and R. M. Dickson, "Highly fluorescent, water-soluble, size-tunable gold quantum dots," Phys. Rev. Lett. 93, 077402 (2004).
[CrossRef] [PubMed]

M. A. El-Sayed, "Small is different: shape-, size-, and composition-dependent properties of some colloidal semiconductor nanocrystals," Acc. Chem. Res. 37, 326-333 (2004).
[CrossRef] [PubMed]

2003 (2)

R. M. Penner, "Hybrid electrochemical/chemical synthesis of quantum dots," Acc. Chem. Res. 33, 78-86 (2003).
[CrossRef]

J.-P. Knemeyer, D.-P. Herten, and M. Sauer, "Detection and identification of single molecules in living cells using spectrally resolved fluorescence lifetime imaging microscopy," Anal. Chem. 75, 2147-2153 (2003).
[CrossRef] [PubMed]

2002 (2)

P. V. Kamat, "Photophysical, photochemical and photocatalytic aspects of metal nanoparticles," J. Phys. Chem. B 106, 7729 (2002).
[CrossRef]

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

2001 (5)

C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
[CrossRef]

J. R. Reimers and N. S. Hush, "The need for quantum-mechanical treatment of capacitance and related properties of nanoelectrodes," J. Phys. Chem. B 105, 8979-8988 (2001).
[CrossRef]

T. Huang, and R. W. Murray, "Visible luminescence of water-soluble monolayer-protected gold clusters," J. Phys. Chem. B 105, 12498-12502 (2001).
[CrossRef]

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

V. Ntziachristos and B. Chance, "Breast imaging technology: Probing physiology and molecular function using optical imaging - applications to breast cancer," Breast Cancer Res. 3, 41-46 (2001).
[CrossRef] [PubMed]

2000 (2)

D. J. Hawrysz and E. M. Sevick-Muraca, "Developments toward diagnostic breast cancer imaging using near-infrared optical measurements and fluorescent contrast agents," Neoplasia 2, 388-417(2000).
[CrossRef]

T. P. Bigioni, R. L. Whetten, and O. Dag, "Near-infrared luminescence from small gold nanocrystals," J. Phys. Chem. B 104, 6983-6986 (2000).
[CrossRef]

1999 (2)

R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
[CrossRef]

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

1997 (1)

R. S. Ingram, M. J. Hostetler, and R. W. Murray, "Poly-hetero--functionalized alkanethiolate-stabilized gold cluster compounds," J. Am. Chem. Soc. 119, 9175-9178 (1997).
[CrossRef]

1968 (1)

W. Stöber, A. Fink, E. Bohn, "A novel method for synthesis of silica nanoparticles," J. Colloid Interface Sci. 26, 62-68 (1968).

Antoku, Y.

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

Astruc, D.

M.-C. Daniel and D. Astruc, "Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology," Chem. Rev. 104, 293-346 (2004).
[CrossRef] [PubMed]

Beeby, A.

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

Bigioni, T. P.

T. P. Bigioni, R. L. Whetten, and O. Dag, "Near-infrared luminescence from small gold nanocrystals," J. Phys. Chem. B 104, 6983-6986 (2000).
[CrossRef]

Bogdanov, A.

R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
[CrossRef]

Bohn, E.

W. Stöber, A. Fink, E. Bohn, "A novel method for synthesis of silica nanoparticles," J. Colloid Interface Sci. 26, 62-68 (1968).

Braun, M.

C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
[CrossRef]

Burda, C.

C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
[CrossRef]

Chance, B.

V. Ntziachristos and B. Chance, "Breast imaging technology: Probing physiology and molecular function using optical imaging - applications to breast cancer," Breast Cancer Res. 3, 41-46 (2001).
[CrossRef] [PubMed]

Choi, J.-P.

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

Chowdhury, M. H.

J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
[CrossRef] [PubMed]

Collier, C. P.

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Concepcion, G. M.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Crespo, O.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Dag, O.

T. P. Bigioni, R. L. Whetten, and O. Dag, "Near-infrared luminescence from small gold nanocrystals," J. Phys. Chem. B 104, 6983-6986 (2000).
[CrossRef]

Daniel, M.-C.

M.-C. Daniel and D. Astruc, "Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology," Chem. Rev. 104, 293-346 (2004).
[CrossRef] [PubMed]

Deaton, J.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Dickson, R. M.

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

J. Zheng, C. Zhang, and R. M. Dickson, "Highly fluorescent, water-soluble, size-tunable gold quantum dots," Phys. Rev. Lett. 93, 077402 (2004).
[CrossRef] [PubMed]

Eisenberg, R.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

El-Sayed, M. A.

M. A. El-Sayed, "Small is different: shape-, size-, and composition-dependent properties of some colloidal semiconductor nanocrystals," Acc. Chem. Res. 37, 326-333 (2004).
[CrossRef] [PubMed]

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
[CrossRef]

Fink, A.

W. Stöber, A. Fink, E. Bohn, "A novel method for synthesis of silica nanoparticles," J. Colloid Interface Sci. 26, 62-68 (1968).

FitzGerald, S.

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

Fu, Y.

J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
[CrossRef] [PubMed]

J. Zhang, Y. Fu, and J. R. Lakowicz, "Dye-labeled silver nanoshell-bright particle," J. Phys. Chem. B. 110, 8986-8991 (2006).
[CrossRef] [PubMed]

Geddes, C. D.

J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
[CrossRef]

Gonzalez, J. I.

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

Guo, R.

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

Gysling, H. J.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Hawrysz, D. J.

D. J. Hawrysz and E. M. Sevick-Muraca, "Developments toward diagnostic breast cancer imaging using near-infrared optical measurements and fluorescent contrast agents," Neoplasia 2, 388-417(2000).
[CrossRef]

Heath, J. R.

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Henrichs, S. E.

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Herten, D.-P.

J.-P. Knemeyer, D.-P. Herten, and M. Sauer, "Detection and identification of single molecules in living cells using spectrally resolved fluorescence lifetime imaging microscopy," Anal. Chem. 75, 2147-2153 (2003).
[CrossRef] [PubMed]

Hostetler, M. J.

R. S. Ingram, M. J. Hostetler, and R. W. Murray, "Poly-hetero--functionalized alkanethiolate-stabilized gold cluster compounds," J. Am. Chem. Soc. 119, 9175-9178 (1997).
[CrossRef]

Hsiang, J.-C.

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

Huang, T.

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

T. Huang, and R. W. Murray, "Visible luminescence of water-soluble monolayer-protected gold clusters," J. Phys. Chem. B 105, 12498-12502 (2001).
[CrossRef]

Hush, N. S.

J. R. Reimers and N. S. Hush, "The need for quantum-mechanical treatment of capacitance and related properties of nanoelectrodes," J. Phys. Chem. B 105, 8979-8988 (2001).
[CrossRef]

Ingram, R. S.

R. S. Ingram, M. J. Hostetler, and R. W. Murray, "Poly-hetero--functionalized alkanethiolate-stabilized gold cluster compounds," J. Am. Chem. Soc. 119, 9175-9178 (1997).
[CrossRef]

Kalyuzhny, G.

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

Kamat, P. V.

P. V. Kamat, "Photophysical, photochemical and photocatalytic aspects of metal nanoparticles," J. Phys. Chem. B 106, 7729 (2002).
[CrossRef]

Knemeyer, J.-P.

J.-P. Knemeyer, D.-P. Herten, and M. Sauer, "Detection and identification of single molecules in living cells using spectrally resolved fluorescence lifetime imaging microscopy," Anal. Chem. 75, 2147-2153 (2003).
[CrossRef] [PubMed]

Laguna, A.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Lakowicz, J. R.

J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
[CrossRef] [PubMed]

J. Zhang, Y. Fu, and J. R. Lakowicz, "Dye-labeled silver nanoshell-bright particle," J. Phys. Chem. B. 110, 8986-8991 (2006).
[CrossRef] [PubMed]

J. Zhang and J. R. Lakowicz, "Enhanced luminescence of phenyl-phenanthridine dye on aggregated small silver nanoparticles," J. Phys. Chem. B. 109, 8701-8706 (2005).
[CrossRef]

J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
[CrossRef]

Landes, C.

C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
[CrossRef]

Larraz, C.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Lee, Y.-A.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Levine, R. D.

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Link, S.

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

Mahmood, U.

R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
[CrossRef]

Markovich, G.

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Menard, L.

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

Mirkin, C. A.

N. L. Rosi, and C. A. Mirkin, "Nanostructures in biodiagnostics," Chem. Rev. 105, 1547-1562 (2005).
[CrossRef] [PubMed]

Murray, R. W.

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

T. Huang, and R. W. Murray, "Visible luminescence of water-soluble monolayer-protected gold clusters," J. Phys. Chem. B 105, 12498-12502 (2001).
[CrossRef]

R. S. Ingram, M. J. Hostetler, and R. W. Murray, "Poly-hetero--functionalized alkanethiolate-stabilized gold cluster compounds," J. Am. Chem. Soc. 119, 9175-9178 (1997).
[CrossRef]

Nakajima, T.

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Nakanishi, J.

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Ntziachristos, V.

V. Ntziachristos and B. Chance, "Breast imaging technology: Probing physiology and molecular function using optical imaging - applications to breast cancer," Breast Cancer Res. 3, 41-46 (2001).
[CrossRef] [PubMed]

Nuzzo, R. G.

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

Ozawa, T.

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Penner, R. M.

R. M. Penner, "Hybrid electrochemical/chemical synthesis of quantum dots," Acc. Chem. Res. 33, 78-86 (2003).
[CrossRef]

Reimers, J. R.

J. R. Reimers and N. S. Hush, "The need for quantum-mechanical treatment of capacitance and related properties of nanoelectrodes," J. Phys. Chem. B 105, 8979-8988 (2001).
[CrossRef]

Remacle, F.

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Richards, C. I.

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

Roll, D.

J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
[CrossRef]

Rosi, N. L.

N. L. Rosi, and C. A. Mirkin, "Nanostructures in biodiagnostics," Chem. Rev. 105, 1547-1562 (2005).
[CrossRef] [PubMed]

Sato, M.

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Sauer, M.

J.-P. Knemeyer, D.-P. Herten, and M. Sauer, "Detection and identification of single molecules in living cells using spectrally resolved fluorescence lifetime imaging microscopy," Anal. Chem. 75, 2147-2153 (2003).
[CrossRef] [PubMed]

Schaaff, T. G.

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

Sevick-Muraca, E. M.

D. J. Hawrysz and E. M. Sevick-Muraca, "Developments toward diagnostic breast cancer imaging using near-infrared optical measurements and fluorescent contrast agents," Neoplasia 2, 388-417(2000).
[CrossRef]

Stöber, W.

W. Stöber, A. Fink, E. Bohn, "A novel method for synthesis of silica nanoparticles," J. Colloid Interface Sci. 26, 62-68 (1968).

Tang, C.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Tohda, K.

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Tung, C. H.

R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
[CrossRef]

Umezawa, Y.

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Villacampa, M. D.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Vosch, T.

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

Wang, G.

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

Wang, Q.-M.

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

Weissleder, R.

R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
[CrossRef]

Whetten, R. L.

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

T. P. Bigioni, R. L. Whetten, and O. Dag, "Near-infrared luminescence from small gold nanocrystals," J. Phys. Chem. B 104, 6983-6986 (2000).
[CrossRef]

Zhang, C.

J. Zheng, C. Zhang, and R. M. Dickson, "Highly fluorescent, water-soluble, size-tunable gold quantum dots," Phys. Rev. Lett. 93, 077402 (2004).
[CrossRef] [PubMed]

Zhang, J.

J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
[CrossRef] [PubMed]

J. Zhang, Y. Fu, and J. R. Lakowicz, "Dye-labeled silver nanoshell-bright particle," J. Phys. Chem. B. 110, 8986-8991 (2006).
[CrossRef] [PubMed]

J. Zhang and J. R. Lakowicz, "Enhanced luminescence of phenyl-phenanthridine dye on aggregated small silver nanoparticles," J. Phys. Chem. B. 109, 8701-8706 (2005).
[CrossRef]

J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
[CrossRef]

Zheng, J.

J. Zheng, C. Zhang, and R. M. Dickson, "Highly fluorescent, water-soluble, size-tunable gold quantum dots," Phys. Rev. Lett. 93, 077402 (2004).
[CrossRef] [PubMed]

Acc. Chem. Res. (3)

M. A. El-Sayed, "Small is different: shape-, size-, and composition-dependent properties of some colloidal semiconductor nanocrystals," Acc. Chem. Res. 37, 326-333 (2004).
[CrossRef] [PubMed]

R. M. Penner, "Hybrid electrochemical/chemical synthesis of quantum dots," Acc. Chem. Res. 33, 78-86 (2003).
[CrossRef]

G. Markovich, C. P. Collier, S. E. Henrichs, F. Remacle, R. D. Levine, and J. R. Heath, "Architectonic quantum dot solids," Acc. Chem. Res. 32, 415-423 (1999).
[CrossRef]

Anal. Chem. (2)

J.-P. Knemeyer, D.-P. Herten, and M. Sauer, "Detection and identification of single molecules in living cells using spectrally resolved fluorescence lifetime imaging microscopy," Anal. Chem. 75, 2147-2153 (2003).
[CrossRef] [PubMed]

J. Nakanishi, T. Nakajima, M. Sato, T. Ozawa, K. Tohda, and Y. Umezawa, "Imaging of conformational changes of proteins with a new environment-sensitive fluorescent probe designed for site-specific labeling of recombinant proteins in live cells," Anal. Chem. 73, 2920-2928 (2001).
[CrossRef] [PubMed]

Breast Cancer Res. (1)

V. Ntziachristos and B. Chance, "Breast imaging technology: Probing physiology and molecular function using optical imaging - applications to breast cancer," Breast Cancer Res. 3, 41-46 (2001).
[CrossRef] [PubMed]

Chem. Rev. (2)

M.-C. Daniel and D. Astruc, "Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology," Chem. Rev. 104, 293-346 (2004).
[CrossRef] [PubMed]

N. L. Rosi, and C. A. Mirkin, "Nanostructures in biodiagnostics," Chem. Rev. 105, 1547-1562 (2005).
[CrossRef] [PubMed]

J. Am. Chem. Soc. (3)

Q.-M. Wang, Y.-A. Lee, O. Crespo, J. Deaton, C. Tang, H. J. Gysling, G. M. Concepcion, C. Larraz, M. D. Villacampa, A. Laguna, and R. Eisenberg, "Intensely luminescent gold(I)-silver(I) cluster complexes with tunable structural features, J. Am. Chem. Soc. 126, 9488-9489 (2004).
[CrossRef] [PubMed]

G. Wang, T. Huang, R. W. Murray, L. Menard, and R. G. Nuzzo, "Near-IR luminescence of monolayer-protected metal clusters," J. Am. Chem. Soc. 127, 812-813 (2005).
[CrossRef] [PubMed]

R. S. Ingram, M. J. Hostetler, and R. W. Murray, "Poly-hetero--functionalized alkanethiolate-stabilized gold cluster compounds," J. Am. Chem. Soc. 119, 9175-9178 (1997).
[CrossRef]

J. Colloid Interface Sci. (1)

W. Stöber, A. Fink, E. Bohn, "A novel method for synthesis of silica nanoparticles," J. Colloid Interface Sci. 26, 62-68 (1968).

J. Phys. Chem. B (6)

J. Zhang, D. Roll, C. D. Geddes, and J. R. Lakowicz, "Aggregation of silver nanoparticle-dextran adducts with concanavalin A and competitive complexation with glucose," J. Phys. Chem. B 108, 12210-12214 (2004).
[CrossRef]

P. V. Kamat, "Photophysical, photochemical and photocatalytic aspects of metal nanoparticles," J. Phys. Chem. B 106, 7729 (2002).
[CrossRef]

T. Huang, and R. W. Murray, "Visible luminescence of water-soluble monolayer-protected gold clusters," J. Phys. Chem. B 105, 12498-12502 (2001).
[CrossRef]

T. P. Bigioni, R. L. Whetten, and O. Dag, "Near-infrared luminescence from small gold nanocrystals," J. Phys. Chem. B 104, 6983-6986 (2000).
[CrossRef]

S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, "Visible to infrared luminescence from a 28-Atom gold cluster," J. Phys. Chem. B 106, 3410-3415 (2002).
[CrossRef]

J. R. Reimers and N. S. Hush, "The need for quantum-mechanical treatment of capacitance and related properties of nanoelectrodes," J. Phys. Chem. B 105, 8979-8988 (2001).
[CrossRef]

J. Phys. Chem. B. (3)

G. Wang, R. Guo, G. Kalyuzhny, J.-P. Choi, and R. W. Murray, "NIR luminescence intensities increase linearly with proportion of polar thiolate ligands in protecting monolayers of Au38 and Au140 quantum dots," J. Phys. Chem. B. 110, 20282-20289 (2006).
[CrossRef] [PubMed]

J. Zhang and J. R. Lakowicz, "Enhanced luminescence of phenyl-phenanthridine dye on aggregated small silver nanoparticles," J. Phys. Chem. B. 109, 8701-8706 (2005).
[CrossRef]

J. Zhang, Y. Fu, and J. R. Lakowicz, "Dye-labeled silver nanoshell-bright particle," J. Phys. Chem. B. 110, 8986-8991 (2006).
[CrossRef] [PubMed]

Nano Lett. (2)

J. Zhang, Y. Fu, M. H. Chowdhury, and J. R. Lakowicz, "Metal-enhanced single-molecule fluorescence on silver particle monomer and dimer: coupling effect between metal particles," Nano Lett. 7, 2101-2107 (2007).
[CrossRef] [PubMed]

C. Landes, M. Braun, C. Burda, and M. A. El-Sayed, "Observation of large changes in the band gap absorption energy of small CdSe nanoparticles induced by the adsorption of a strong hole acceptor" Nano Lett. 1, 667-670 (2001).
[CrossRef]

Nature Biotechnol. (1)

R. Weissleder, C. H. Tung, U. Mahmood, and A. BogdanovJr., "A in vivo imaging of tumors with protease-activated near-infrared fluorescent probes," Nature Biotechnol. 17, 375-378 (1999).
[CrossRef]

Neoplasia (1)

D. J. Hawrysz and E. M. Sevick-Muraca, "Developments toward diagnostic breast cancer imaging using near-infrared optical measurements and fluorescent contrast agents," Neoplasia 2, 388-417(2000).
[CrossRef]

Phys. Rev. Lett. (1)

J. Zheng, C. Zhang, and R. M. Dickson, "Highly fluorescent, water-soluble, size-tunable gold quantum dots," Phys. Rev. Lett. 93, 077402 (2004).
[CrossRef] [PubMed]

PNAS (1)

T. Vosch, Y. Antoku, J.-C. Hsiang, C. I. Richards, J. I. Gonzalez, and R. M. Dickson, "Strongly emissive individual DNA-encapsulated Ag nanoclusters as single-molecule fluorophores," PNAS 104, 12616-12621 (2007).
[CrossRef] [PubMed]

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Scheme 1.
Scheme 1.

Labeling the aminated silica beads with the luminescent succinimidylated Au particles by condensation.

Fig. 1.
Fig. 1.

Absorbance and luminescence spectral changes of free and bound Au particles on the silica beads in water. Luminescence spectra were measured upon excitation at 470 nm.

Fig. 2.
Fig. 2.

TEM images of (a) free Au particles, (b) free silica beads, and (c) Au particle labeled-silica beads when the molar ratio of metal particle/silica bead was 50.

Fig. 3.
Fig. 3.

Emission images of free Au particles, Au particle labeled-silica beads when the molar ratio of metal particle/silica bead was 10, Au particle labeled-silica beads when the molar ratio of metal particle/silica bead was 50, and free silica beads without the bound metal particles. The right panels are time traces of free Au particles and Au particle labeled silica beads when the molar ratio was 10 as well as free Cy5 as comparison.

Metrics