, Volume 8, Issue 2, pp 685–691 | Cite as

The Effect of Aspect Ratio of Gold Nanorods on Cell Imaging with Two-Photon Excitation



To make the gold nanorod (AuNR) a better photoluminescence (PL) probe for cell imaging under two-photon excitation (TPE), the effect of the aspect ratio of AuNRs was studied. The AuNRs with the aspect ratios of 2.7, 3.2, 4.1, and 4.5 and correlated longitudinal surface plasmon resonance (LSPR) bands of 710, 760, 820, and 870 nm were compared. The approach of two-photon excited PL was used to measure the two-photon absorption cross section (TPACS) of these AuNRs in aqueous solutions. Under TPE of an 800-nm femtosecond laser, the TPACS of AuNRs with an aspect ratio of 3.2 was found to be the highest (about 3 × 109 GM), and that of AuNRs (aspect ratio of 2.7) was only 1.5 × 109 GM. The probe function of these two AuNRs was further compared in cell imaging studies using the human liver cancer cell (QGY) as the cell model. Both TPE PL image and confocal reflectance image of AuNR-loaded cells were acquired comparatively in measurements. The brightness and contrast of confocal reflectance images for these two AuNRs in cells are similar. In contrast, the PL images of cellular AuNRs (2.7) under TPE of 800 nm are weak but that of cellular AuNRs (3.2) is much better. These results show that when the LSPR band of AuNRs is coincided with the excitation wavelength, the TPACS of these AuNRs will be enhanced ensuring a good quality of cell imaging under TPE. The LSPR band is correlated to the aspect ratio of AuNRs. Therefore, in cell imaging studies with TPE, the aspect ratio effect of AuNRs should be taken into consideration.


Gold nanoparticles Two-photon excitation absorption cross section Two-photon photoluminescence Cell imaging Surface plasmon resonance 


  1. 1.
    So PTC, Kim H, Kochevar IE (1998) Two-photo deep tissue ex vivo imaging of mouse dermal and subcutaneous structures. Opt Express 3:339–350CrossRefGoogle Scholar
  2. 2.
    Zheng S, Chen JY, Wang PN, Yang WL, Zhou LW (2010) Measuring the two-photon absorption cross sections of thiol-capped CdTe quantum dots in living cells. Appl Phys Lett 97:173703CrossRefGoogle Scholar
  3. 3.
    Pawlicki M, Collins HA, Denning RG, Anderson HLT (2009) Two-photon absorption and design of two-photon dyes. Chem Int Ed 48:3244–3266CrossRefGoogle Scholar
  4. 4.
    Hainfeld JF, Slatkin DN, Smilowitz HM (2004) The use of gold nanoparticles to enhance radiotherapy in mice. Phys Med Biol 49:N309–N315CrossRefGoogle Scholar
  5. 5.
    Huff TB, Tong L, Zhao Y, Hansen MN, Cheng JX, Wei L (2007) Hyperthermic effects of gold nanorods on tumor cells. Nanomedicine 2:125–132CrossRefGoogle Scholar
  6. 6.
    Durr NJ, Larson T, Smith DK, Korgel BA, Sokolov K, Ben-Yakar A (2007) Two-photon luminescence imaging of cancer cells using molecularly targeted gold nanorods. Nano Lett 7:941–945CrossRefGoogle Scholar
  7. 7.
    Hauck TS, Ghazani AA, Chan WCW (2008) Assessing the effect of surface chemistry on gold nanorod uptack, toxicity, and gene expression in mammalian cells. Small 4:153–159CrossRefGoogle Scholar
  8. 8.
    Avram M, Balan CM, Petrescu I, Schiopu V, Marculescu C, Avram A (2012) Gold nanoparticle uptake by tumour cells of B16 mouse melanoma. Plasmonics 7:717–724CrossRefGoogle Scholar
  9. 9.
    Yong KT, Swihart MT, Ding H, Prasad PN (2009) Preparation of gold nanoparticles and their applications in anisotropic nanoparticle synthesis and bioimaging. Plasmonics 4:79–93CrossRefGoogle Scholar
  10. 10.
    Link S, El-Sayed MA (1999) Size and temperature dependence of the plasmon absorption of colloidal gold nanoparticles. J Phys Chem B 103:4212–4217CrossRefGoogle Scholar
  11. 11.
    Eustis S, El-Sayed MA (2005) Dependence of the enhanced fluorescence intensity of gold nanorods: experimental and simulation study. J Phys Chem B 109:16350–16356CrossRefGoogle Scholar
  12. 12.
    Wu X, Ming T, Wang X, Wang PN, Wang JF, Chen JY (2010) High-photoluminescence-yield gold nanocubes: for cell imaging and photothermal therapy. ACS Nano 4:113–120CrossRefGoogle Scholar
  13. 13.
    Park J, Estrada A, Sharp K, Sang K, Schwartz JA, Smith DK, Coleman C, Payne JD, Korgel BA, Dunn AK (2008) Two-photon-induced photoluminescence imaging of tumors using near-infrared excited gold nanoshells. Opt Express 16:1590–1599CrossRefGoogle Scholar
  14. 14.
    Wang HF, Huff TB, Zweifel DA, He W, Low PS, Wei A, Cheng JX (2005) In vitro and in vivo two-photon luminescence imaging of single gold nanorods. Proc Natl Acad Sci USA 102:15752–15756CrossRefGoogle Scholar
  15. 15.
    Huff TB, Hansen MN, Zhao Y, Cheng JX, Wei A (2007) Controlling the cellular uptake of gold nanorods. Langmuir 23:1596–1599CrossRefGoogle Scholar
  16. 16.
    Ni WH, Kou XS, Yang Z, Wang JF (2008) Tailoring longitudinal surface plasmon wavelengths, scattering and absorption cross sections of gold nanorods. ACS Nano 2:677–686CrossRefGoogle Scholar
  17. 17.
    Sau TK, Murphy CJ (2004) Room temperature, high-yield synthesis of multiple shapes of gold nanoparticles in aqueous solution. J Am Chem Soc 126:8648–8649CrossRefGoogle Scholar
  18. 18.
    Kou XS, Ni WH, Tsung CK, Chan K, Lin HQ, Stucky GD, Wang JF (2007) Growth of gold bipyramids with improved yield and their curvature-directed oxidation. Small 3:2103–2113CrossRefGoogle Scholar
  19. 19.
    Zhao FL, Fan HH, Zhang R, Wang HZ (2009) Multi-photo absorption of heterocyclic molecules. Trends Heterocycl Chem 14:91–116Google Scholar
  20. 20.
    Fischer A, Cremer C, Stelzer EHK (1995) Fluorescence of coumarins and xanthenes after two-photon absorption with a pulsed titanium–sapphire laser. Appl Opt 34:1989–2003CrossRefGoogle Scholar
  21. 21.
    Xu C, Webb WW (1996) Measurement of two-photon excitation cross sections of molecular fluorophores with data from 690 to 1050 nm. J Opt Soc Am B 13:481–491CrossRefGoogle Scholar
  22. 22.
    Hauck TS, Jennings TL, Yatsenko T, Kumaradas JC, Chan WCW (2008) Enhancing the toxicity of cancer chemotherapeutics with gold nanorod hyperthermia. Adv Mater 20:3832–3838CrossRefGoogle Scholar
  23. 23.
    Huang XH, El-sayed IH, Qian W, El-sayed MA (2006) Cancer cell imaging and photothermal therapy in near-infrared region by using gold nanorods. J Am Chem Soc 128:2115–2120CrossRefGoogle Scholar
  24. 24.
    Goh D, Gong T, Dinish US, Maiti KK, Fu CY, Yong KT, Olivo M (2012) Pluronic triblock copolymer encapsulated gold nanorods as biocompatible localized plasmon resonance-enhanced scattering probes for dark-field imaging of cancer cells. Plasmonics 7:595–601CrossRefGoogle Scholar
  25. 25.
    Wu X, Yang F, Ming T, Xiong RL, Wang PN, Chen JY (2011) Au nanorods can be used for long-term cell imaging? Appl Phys Lett 98:213704CrossRefGoogle Scholar
  26. 26.
    Bouhelier A, Bachelot R, Lerondel G, Kostcheev S, Royer P, Wiederrecht GP (2005) Surface plasmon characteristics of tunable photoluminescence in single gold nanorods. Phys Rev Lett 95:267405CrossRefGoogle Scholar
  27. 27.
    Zijlstra P, Chou JWM, Min G (2009) Five-dimensional optical recording mediated by surface plasmons in gold nanorods. Nature 459:410–413CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  1. 1.State Key Laboratory of Surface Physics and Department of Physics, and the Key Laboratory of Micro/Nano Photonics Structure (Ministry of Education)Fudan UniversityShanghaiChina
  2. 2.Department of PhysicsFudan UniversityShanghaiPeople’s Republic of China

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