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Robust gold nanorods stabilized by bidentate N-heterocyclic-carbene–thiolate ligands

Abstract

Although N-heterocyclic carbenes (NHCs) have demonstrated outstanding potential for use as surface anchors, synthetic challenges have limited their application to either large planar substrates or very small spherical nanoparticles. The development of a strategy to graft NHCs onto non-spherical nanomaterials, such as gold nanorods, would greatly expand their utility as surface ligands. Here, we use a bidentate thiolate–NHC–gold(i) complex that is easily grafted onto commercial cetyl trimethylammonium bromide-stabilized gold nanorods through ligand exchange. On mild reduction of the resulting surface-tethered NHC–gold(i) complexes, the gold atom attached to the NHC complex is added to the surface as an adatom, thereby precluding the need for reorganization of the underlying surface lattice upon NHC binding. The resulting thiolate–NHC-stabilized gold nanorods are stable towards excess glutathione for up to six days, and under conditions with large variations in pH, high and low temperatures, high salt concentrations, or in biological media and cell culture. We also demonstrate the utility of these nanorods for in vitro photothermal therapy.

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Fig. 1: Strategies for installation of NHCs onto gold nanomaterials.
Fig. 2: Synthesis and molecular characterization of PEGylated masked bidentate ligands.
Fig. 3: Installation of masked NHC–thiolate ligands onto commercial CTAB@Au nanorods.
Fig. 4: Characterization of NHC@Au-I.
Fig. 5: DFT calculations.
Fig. 6: Preliminary biological investigations using NHC@Au-I.

Data availability

All data supporting the findings of this study are available within the Article and its Supplementary Information, and/or from the corresponding author upon reasonable request.

References

  1. 1.

    Zhukhovitskiy, A. V., MacLeod, M. J. & Johnson, J. A. Carbene ligands in surface chemistry: from stabilization of discrete elemental allotropes to modification of nanoscale and bulk substrates. Chem. Rev. 115, 11503–11532 (2015).

    CAS  Article  PubMed  Google Scholar 

  2. 2.

    Hopkinson, M. N., Richter, C., Schedler, M. & Glorius, F. An overview of N-heterocyclic carbenes. Nature 510, 485–496 (2014).

    CAS  Article  PubMed  Google Scholar 

  3. 3.

    Ranganath, K. V. S., Kloesges, J., Schäfer, A. H. & Glorius, F. Asymmetric nanocatalysis: N-heterocyclic carbenes as chiral modifiers of Fe3O4/Pd nanoparticles. Angew. Chem. Int. Ed. 49, 7786–7789 (2010).

    CAS  Article  Google Scholar 

  4. 4.

    Ranganath, K. V. S., Schäfer, A. H. & Glorius, F. Comparison of superparamagnetic Fe3O4-supported N-heterocyclic carbene-based catalysts for enantioselective allylation. ChemCatChem 3, 1889–1891 (2011).

    CAS  Article  Google Scholar 

  5. 5.

    Serpell, C. J., Cookson, J., Thompson, A. L., Brown, C. M. & Beer, P. D. Haloaurate and halopalladate imidazolium salts: structures, properties, and use as precursors for catalytic metal nanoparticles. Dalton Trans. 42, 1385–1393 (2013).

    CAS  Article  PubMed  Google Scholar 

  6. 6.

    Richter, C., Schaepe, K., Glorius, F. & Ravoo, B. J. Tailor-made N-heterocyclic carbenes for nanoparticle stabilization. Chem. Commun. 50, 3204–3207 (2014).

    CAS  Article  Google Scholar 

  7. 7.

    Ferry, A. et al. Negatively charged N-heterocyclic carbene-stabilized Pd and Au nanoparticles and efficient catalysis in water. ACS Catal. 5, 5414–5420 (2015).

    CAS  Article  Google Scholar 

  8. 8.

    Rühling, A. et al. Modular bidentate hybrid NHC–thioether ligands for the stabilization of palladium nanoparticles in various solvents. Angew. Chem. Int. Ed. 55, 5856–5860 (2016).

    Article  Google Scholar 

  9. 9.

    Soulé, J.-F., Miyamura, H. & Kobayashi, S. Copolymer-incarcerated nickel nanoparticles with N-heterocyclic carbene precursors as active cross-linking agents for Corriu–Kumada–Tamao reaction. J. Am. Chem. Soc. 135, 10602–10605 (2013).

    Article  PubMed  Google Scholar 

  10. 10.

    de los Bernardos, M. D., Pérez-Rodríguez, S., Gual, A., Claver, C. & Godard, C. Facile synthesis of NHC-stabilized Ni nanoparticles and their catalytic application in the Z-selective hydrogenation of alkynes. Chem. Commun. 53, 7894–7897 (2017).

    Article  Google Scholar 

  11. 11.

    Lara, P., Suárez, A., Collière, V., Philippot, K. & Chaudret, B. Platinum N-heterocyclic carbene nanoparticles as new and effective catalysts for the selective hydrogenation of nitroaromatics. ChemCatChem 6, 87–90 (2014).

    CAS  Article  Google Scholar 

  12. 12.

    Lara, P. et al. Ruthenium nanoparticles stabilized by N-heterocyclic carbenes: ligand location and influence on reactivity. Angew. Chem. Int. Ed. 50, 12080–12084 (2011).

    CAS  Article  Google Scholar 

  13. 13.

    Gonzalez-Galvez, D. et al. NHC-stabilized ruthenium nanoparticles as new catalysts for the hydrogenation of aromatics. Catal. Sci. Tech. 3, 99–105 (2013).

    CAS  Article  Google Scholar 

  14. 14.

    Lara, P. et al. NHC-stabilized Ru nanoparticles: synthesis and surface studies. Nano-Structures Nano-Objects 6, 39–45 (2016).

    CAS  Article  Google Scholar 

  15. 15.

    Martínez-Prieto, L. M. et al. Long-chain NHC-stabilized RuNPs as versatile catalysts for one-pot oxidation/hydrogenation reactions. Chem. Commun. 52, 4768–4771 (2016).

    Article  Google Scholar 

  16. 16.

    Ernst, J. B., Muratsugu, S., Wang, F., Tada, M. & Glorius, F. Tunable heterogeneous catalysis: N-heterocyclic carbenes as ligands for supported heterogeneous Ru/K-Al2O3 catalysts to tune reactivity and selectivity. J. Am. Chem. Soc. 138, 10718–10721 (2016).

    CAS  Article  PubMed  Google Scholar 

  17. 17.

    Song, S. G. et al. N-Heterocyclic carbene-based conducting polymer–gold nanoparticle hybrids and their catalytic application. Macromolecules 47, 6566–6571 (2014).

    CAS  Article  Google Scholar 

  18. 18.

    Crespo, J. et al. Ultrasmall NHC-coated gold nanoparticles obtained through solvent free thermolysis of organometallic Au(i) complexes. Dalton Trans. 43, 15713–15718 (2014).

    CAS  Article  PubMed  Google Scholar 

  19. 19.

    Cao, Z. et al. A molecular surface functionalization approach to tuning nanoparticle electrocatalysts for carbon dioxide reduction. J. Am. Chem. Soc. 138, 8120–8125 (2016).

    CAS  Article  PubMed  Google Scholar 

  20. 20.

    Ye, R. et al. Supported Au nanoparticles with N-heterocyclic carbene ligands as active and stable heterogeneous catalysts for lactonization. J. Am. Chem. Soc. 140, 4144–4149 (2018).

    CAS  Article  PubMed  Google Scholar 

  21. 21.

    MacLeod, M. J. & Johnson, J. A. PEGylated N-heterocyclic carbene anchors designed to stabilize gold nanoparticles in biologically relevant media. J. Am. Chem. Soc. 137, 7974–7977 (2015).

    CAS  Article  PubMed  Google Scholar 

  22. 22.

    Salorinne, K. et al. Water-soluble N-heterocyclic carbene-protected gold nanoparticles: size-controlled synthesis, stability, and optical properties. Angew. Chem. Int. Ed. 56, 6198–6202 (2017).

    CAS  Article  Google Scholar 

  23. 23.

    Zhukhovitskiy, A. V., Mavros, M. G., Van Voorhis, T. & Johnson, J. A. Addressable carbene anchors for gold surfaces. J. Am. Chem. Soc. 135, 7418–7421 (2013).

    CAS  Article  PubMed  Google Scholar 

  24. 24.

    Crudden, C. M. et al. Ultra stable self-assembled monolayers of N-heterocyclic carbenes on gold. Nat. Chem. 6, 409–414 (2014).

    CAS  Article  PubMed  Google Scholar 

  25. 25.

    Crudden, C. M. et al. Simple direct formation of self-assembled N-heterocyclic carbene monolayers on gold and their application in biosensing. Nat. Commun. 7, 12654 (2016).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  26. 26.

    Zhukhovitskiy, A. V. et al. Reactions of persistent carbenes with hydrogen-terminated silicon surfaces. J. Am. Chem. Soc. 138, 8639–8652 (2016).

    CAS  Article  PubMed  Google Scholar 

  27. 27.

    Mackey, M. A., Ali, M. R. K., Austin, L. A., Near, R. D. & El-Sayed, M. A. The most effective gold nanorod size for plasmonic photothermal therapy: theory and in vitro experiments. J. Phys. Chem. B 118, 1319–1326 (2014).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  28. 28.

    Grzelczak, M., Pérez-Juste, J., Mulvaney, P. & Liz-Marzán, L. M. Shape control in gold nanoparticle synthesis. Chem. Soc. Rev. 37, 1783–1791 (2008).

    CAS  Article  Google Scholar 

  29. 29.

    Hurst, E. C., Wilson, K., Fairlamb, I. J. S. & Chechik, V. N-Heterocyclic carbene coated metal nanoparticles. New J. Chem. 33, 1837–1840 (2009).

    CAS  Article  Google Scholar 

  30. 30.

    Möller, N. et al. Stabilization of high oxidation state upconversion nanoparticles by N-heterocyclic carbenes. Angew. Chem. Int. Ed. 56, 4356–4360 (2017).

    Article  Google Scholar 

  31. 31.

    Vignolle, J. & Tilley, T. D. N-Heterocyclic carbene-stabilized gold nanoparticles and their assembly into 3D superlattices. Chem. Commun. 2009, 7230–7232 (2009).

    Article  Google Scholar 

  32. 32.

    Ling, X., Roland, S. & Pileni, M. P. Supracrystals of N-heterocyclic carbene-coated Au nanocrystals. Chem. Mater. 27, 414–423 (2015).

    CAS  Article  Google Scholar 

  33. 33.

    Bridonneau, N. et al. N-Heterocyclic carbene-stabilized gold nanoparticles with tunable sizes. Dalton Trans. 47, 6850–6859 (2018).

    CAS  Article  PubMed  Google Scholar 

  34. 34.

    Torrelles, X. et al. Solving the long-standing controversy of long-chain alkanethiols surface structure on Au(111). J. Phys. Chem. C 122, 3893–3902 (2018).

    CAS  Article  Google Scholar 

  35. 35.

    Rodríguez-Castillo, M. et al. Reactivity of gold nanoparticles towards N-heterocyclic carbenes. Dalton Trans. 43, 5978–5982 (2014).

    Article  PubMed  Google Scholar 

  36. 36.

    Wang, G. Q. et al. Ballbot-type motion of N-heterocyclic carbenes on gold surfaces. Nat. Chem. 9, 152–156 (2017).

    CAS  Article  PubMed  Google Scholar 

  37. 37.

    Jiang, L. et al. N-Heterocyclic carbenes on close-packed coinage metal surfaces: bis-carbene metal adatom bonding scheme of monolayer films on Au, Ag and Cu. Chem. Sci. 8, 8301–8308 (2017).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  38. 38.

    Collado, A., Gomez-Suarez, A., Martin, A. R., Slawin, A. M. Z. & Nolan, S. P. Straightforward synthesis of [Au(NHC)X] (NHC = N-heterocyclic carbene, X = Cl, Br, I) complexes. Chem. Commun. 49, 5541–5543 (2013).

    CAS  Article  Google Scholar 

  39. 39.

    Fèvre, M. et al. Imidazolium hydrogen carbonates versus imidazolium carboxylates as organic precatalysts for N-heterocyclic carbene catalyzed reactions. J. Org. Chem. 77, 10135–10144 (2012).

    Article  PubMed  Google Scholar 

  40. 40.

    Li, Z., Jin, R. C., Mirkin, C. A. & Letsinger, R. L. Multiple thiol-anchor capped DNA-gold nanoparticle conjugates. Nucleic Acids Res. 30, 1558–1562 (2002).

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  41. 41.

    Oh, E. et al. Colloidal stability of gold nanoparticles coated with multithiol-poly(ethylene glycol) ligands: importance of structural constraints of the sulfur anchoring groups. J. Phys. Chem. C 117, 18947–18956 (2013).

    CAS  Article  Google Scholar 

  42. 42.

    Oh, E., Susumu, K., Goswami, R. & Mattoussi, H. One-phase synthesis of water-soluble gold nanoparticles with control over size and surface functionalities. Langmuir 26, 7604–7613 (2010).

    CAS  Article  PubMed  Google Scholar 

  43. 43.

    Man, R. W. Y. et al. Ultrastable gold nanoparticles modified by bidentate N-heterocyclic carbene ligands. J. Am. Chem. Soc. 140, 1576–1579 (2018).

    CAS  Article  PubMed  Google Scholar 

  44. 44.

    Cao, Z. et al. Chelating N-heterocyclic carbene ligands enable tuning of electrocatalytic CO2 reduction to formate and carbon monoxide: surface organometallic chemistry. Angew. Chem., Int. Ed. 57, 4981–4985 (2018).

    CAS  Article  Google Scholar 

  45. 45.

    Pillar, V. N. R. Photo-removable protecting groups in organic-synthesis. Synthesis 1980, 1–26 1980).

    Article  Google Scholar 

  46. 46.

    Dreaden, E. C., Alkilany, A. M., Huang, X., Murphy, C. J. & El-Sayed, M. A. The golden age: gold nanoparticles for biomedicine. Chem. Soc. Rev. 41, 2740–2779 (2012).

    CAS  Article  Google Scholar 

  47. 47.

    Otsuka, H., Nagasaki, Y. & Kataoka, K. PEGylated nanoparticles for biological and pharmaceutical applications. Adv. Drug Deliv. Rev. 64, 246–255 (2012).

    Article  Google Scholar 

  48. 48.

    Locatelli, E., Monaco, I. & Franchini, M. C. Surface modifications of gold nanorods for applications in nanomedicine. RSC Adv. 5, 21681–21699 (2015).

    CAS  Article  Google Scholar 

  49. 49.

    Liu, H.-X., He, X. & Zhao, L. Metallamacrocycle-modified gold nanoparticles: a new pathway for surface functionalization. Chem. Commun. 50, 971–974 (2014).

    CAS  Article  Google Scholar 

  50. 50.

    Schulz, F. et al. Effective PEGylation of gold nanorods. Nanoscale 8, 7296–7308 (2016).

    CAS  Article  PubMed  Google Scholar 

  51. 51.

    Khlebtsov, N. & Dykman, L. Biodistribution and toxicity of engineered gold nanoparticles: a review of in vitro and in vivo studies. Chem. Soc. Rev. 40, 1647–1671 (2011).

    CAS  Article  PubMed  Google Scholar 

  52. 52.

    Tang, Q. & Jiang, D. E. Comprehensive view of the ligand gold interface from first principles. Chem. Mater. 29, 6908–6915 (2017).

    CAS  Article  Google Scholar 

  53. 53.

    Schaefer, H. E. Investigation of thermal-equilibrium vacancies in metals by positron-annihilation. Phys. Status Solidi A 102, 47–65 (1987).

    CAS  Article  Google Scholar 

  54. 54.

    Qi, W. H. & Wang, M. P. Vacancy formation energy of small particles. J. Mater. Sci. 39, 2529–2530 (2004).

    CAS  Article  Google Scholar 

  55. 55.

    Huang, X. H., El-Sayed, I. H., Qian, W. & El-Sayed, M. A. Cancer cell imaging and photothermal therapy in the near-infrared region by using gold nanorods. J. Am. Chem. Soc. 128, 2115–2120 (2006).

    CAS  Article  PubMed  Google Scholar 

  56. 56.

    Huang, X. H. & El-Sayed, M. A. Gold nanoparticles: optical properties and implementations in cancer diagnosis and photothermal therapy. J. Adv. Res. 1, 13–28 (2010).

    Article  Google Scholar 

  57. 57.

    Yang, X., Yang, M. X., Pang, B., Vara, M. & Xia, Y. N. Gold nanomaterials at work in biomedicine. Chem. Rev. 115, 10410–10488 (2015).

    CAS  Article  Google Scholar 

  58. 58.

    Doud, E. A. et al. In situ formation of N-heterocyclic carbene-bound single-molecule junctions. J. Am. Chem. Soc. 140, 8944–8949 (2018).

    CAS  Article  PubMed  Google Scholar 

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Acknowledgements

The authors thank the National Science Foundation (CHE-1351646) for support of this work.

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M.J.M. and J.A.J. conceived the idea. M.J.M. conducted all synthesis and characterization studies. A.J.G. conducted laser irradiation experiments. H.Y. and T.V.V. conducted DFT calculations. H.V.-T.N. conducted cell culture assays. M.J.M. and J.A.J. wrote the manuscript. All authors read and revised the manuscript.

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Correspondence to Jeremiah A. Johnson.

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Detailed methods and materials, experimental protocols, characterization data (such as spectral data), Supplementary Figures 1–45 and Supplementary Table 1

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MacLeod, M.J., Goodman, A.J., Ye, HZ. et al. Robust gold nanorods stabilized by bidentate N-heterocyclic-carbene–thiolate ligands. Nature Chem 11, 57–63 (2019). https://doi.org/10.1038/s41557-018-0159-8

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