Optoacoustic detection of viral antigens using targeted gold nanorods

Saher Maswadi, Lee Woodward, Randolph D. Glickman, Norman Barsalou

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


We are detecting antigens (Ag), isolated from infectious organisms, utilizing laser optoacoustic spectroscopy and antibody-coupled gold nanorod (NR) contrast agents specifically targeted to the antigen of interest. We have detected, in clinical ocular samples, both Herpes Simplex Virus Type 1 and 2 (HSV-1 and HSV-2). A monoclonal antibody (Ab) specific to both HSV-1 and HSV-2 was conjugated to gold nanorods to produce a targeted contrast agent with a strong optoacoustic signal. Elutions obtained from patient corneal swabs were adsorbed in standard plastic micro-wells. An immunoaffinity reaction was then performed with the functionalized gold nanorods, and the results were probed with an OPO laser, emitting wavelengths at the peak absorptions of the nanorods. Positive optoacoustic responses were obtained from samples containing authentic (microbiologically confirmed) HSV-1 and HSV-2. To obtain an estimate of the sensitivity of the technique, serial dilutions from 1 mg/ml to 1 pg/ml of a C. trachomatis surface Ag were prepared, and were probed with a monoclonal Ab, specific to the C. trachomatis surface Ag, conjugated to gold nanorods. An optoacoustic response was obtained, proportional to the concentration of antigen, and with a limit of detection of about 5 pg/ml. The optoacoustic signals generated from micro-wells containing albumin or saline were similar to those from blank wells. The potential benefit of this method is identify viral agents more rapidly than with existing techniques. In addition, the sensitivity of the assay is comparable or superior to existing colorimetric- or fluorometric-linked immunoaffinity assays.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
StatePublished - 2009
EventPhotons Plus Ultrasound: Imaging and Sensing 2009 - San Jose, CA, United States
Duration: Jan 25 2009Jan 28 2009


OtherPhotons Plus Ultrasound: Imaging and Sensing 2009
Country/TerritoryUnited States
CitySan Jose, CA


  • Antigen
  • Gold nanorod
  • Herpes simplex virus
  • Laser
  • Optoacoustic
  • Spectroscopy
  • Viral detection

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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