Whole-Blood Immunoassay Facilitated by Gold Nanoshell-Conjugate Antibodies

  • Lee R. Hirsch
  • Naomi J. Halas
  • Jennifer L. West
Protocol
Part of the Methods in Molecular Biology™ book series (MIMB, volume 303)

Abstract

In this chapter, we outline a simple procedure using gold nanoshells as a substrate for an immunoassay that is capable of detecting subnanogram levels of analyte within whole blood on the order of minutes. Unique to metallic nanoshells is their optical tunability over a large range of wavelengths. We describe the design of nanoshells that attenuate light strongly in a region of light where blood does not (i.e., the near infrared [IR]), permitting optical detection of nanoshells in whole blood. We also describe a procedure to monitor the analyte-induced aggregation of antibody-conjugated nanoshells in whole blood using near-IR light. The immunoassay is fast and specific, requires no separation/purification steps, is simple to perform (mix and sit), and uses common laboratory equipment for detection (spectrophotometer). Preparation of the antibodynanoshell conjugates is described, along with the design and optimization of the whole-blood nanoshell-based immunoassay system.

Key Words

Nanoshells immunoassay whole blood silica cores gold colloid 

Notes

Acknowledgments

We wish to thank the National Science Foundation, the MURI program administered by the Army Research Office, and the Robert. A. Welch Foundation for financial support.

References

  1. 1.
    Hirsch, L. R., Jackson, J. B., Lee, A., Halas, N. J., and West, J. L. (2003) A whole blood immunoassay using gold nanoshells. Anal. Chem. 75, 2377–2381.PubMedCrossRefGoogle Scholar
  2. 2.
    Averitt, R. D., Sarkar, D., and Halas, N. J. (1997) Plasmon resonance shifts of Au-coated Au 2 S nanoshells: insight into multicomponent nanoparticle growth. Phys. Rev. Lett. 78, 4217–4220.CrossRefGoogle Scholar
  3. 3.
    Oldenberg, S. J., Averitt, R. D., Westcott, S. L., and Halas, N. J. (1998) Nanoengineering of optical resonances. Chem. Phys. Lett. 288, 243–247.CrossRefGoogle Scholar
  4. 4.
    Duff, D. G., Baiker, A., and Edwards, P. P. (1993) A new hydrosol of gold clusters, 1: formation and particle size variation. Langmuir 9, 2301–2309.CrossRefGoogle Scholar
  5. 5.
    Stöber, W., Fink, A., and Bohn, E. (1968) Controlled growth of monodisperse silica spheres in the micron size range. J. Coll. Interf. Sci. 26, 62–69.CrossRefGoogle Scholar

Copyright information

© Humana Press Inc. 2005

Authors and Affiliations

  • Lee R. Hirsch
    • 1
  • Naomi J. Halas
    • 2
  • Jennifer L. West
    • 1
  1. 1.Department of BioengineeringRice UniversityHouston
  2. 2.Department of Electrical and Computer Engineering and Department of ChemistryRice UniversityHouston

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