May 2007
Volume 48, Issue 13
ARVO Annual Meeting Abstract  |   May 2007
Potential for Detecting Ocular Bacterial Antigen Using Photoacoustic Spectroscopy
Author Affiliations & Notes
  • L. Woodward
    University of Texas Health Science Center, San Antonio, Texas
  • S. Maswadi
    University of Texas Health Science Center, San Antonio, Texas
  • R. D. Glickman
    University of Texas Health Science Center, San Antonio, Texas
  • A. Oraevsky
    Fairway Medical Technologies, Houston, Texas
  • N. Barsalou
    Laser Department, Naval Health Research Center Detachment, Brooks City-Base, San Antonio, Texas
  • G. Zhong
    University of Texas Health Science Center, San Antonio, Texas
    Microbiology and Immunology,
  • Footnotes
    Commercial Relationships L. Woodward, None; S. Maswadi, None; R.D. Glickman, None; A. Oraevsky, Fairway Medical Technologies, E; N. Barsalou, None; G. Zhong, None.
  • Footnotes
    Support RMG Research Fund, Office of Naval Research Grant 5MA485, and Research to Prevent Blindness, Inc.
Investigative Ophthalmology & Visual Science May 2007, Vol.48, 4247. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      L. Woodward, S. Maswadi, R. D. Glickman, A. Oraevsky, N. Barsalou, G. Zhong; Potential for Detecting Ocular Bacterial Antigen Using Photoacoustic Spectroscopy. Invest. Ophthalmol. Vis. Sci. 2007;48(13):4247.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Purpose:: We are investigating the feasibility of detecting ocular bacterial antigen using a minimally invasive optical method based on photoacoustic spectroscopy (PAS). The key technology for implementation of this technique is the utilization of antibody-coupled nanorods as a contrast agent specifically targeted to the antigen of interest.

Methods:: A preparation of 1mg/ml of monoclonal antibody (Ab) specific to C. trachomatis surface antigen (Ag) was conjugated to gold nanorods using standard commercial reagents, in order to produce a targeted contrast agent with a strong photoacoustic signal. The complementary, C. trachomatis surface Ag was adsorbed to the inside walls of plastic spectrophotometer cuvettes to evaluate the binding of the contrast agents in a modified ELISA. Photoacoustic signals were elicited from the bound nanorods, using an optical parametric oscillator (OPO) laser system as the pump. The short pulses (5-10ns) of the OPO increased efficiency of photoacoustic conversion, while the wavelength tuneability of the OPO optimized the spectroscopic measurement by exciting the nanorods at their optical absorption maxima. PAS responses were measured in the cuvettes, containing the Ab-nanorod-Ag complexes, using a probe beam deflection technique, by directing a low-power HeNe laser beam through the optical surfaces of the cuvette and measuring the beam deflection produced by photoacoustic responses.

Results:: The photoacoustic spectrum and the conventional optical absorption spectrum of the solution of C. trachomatis antigen bound to the Ab-conjugated nanorods were found to have absorption peaks at ~750nm, which is consistent with the presence of nanorod contrast agent bound on the cuvette walls.

Conclusions:: These findings indicate that targeted contrast agents can enhance the photoacoustic response of specific biomolecules. Although work is ongoing to optimize the reaction conditions, and to determine the specificity of this method by challenging the binding of contrast agent with non-specific Ab, the present observations indicate that PAS with specific contrast enhancement is a promising method for in vivo applications, such as detection of bacterial antigens.

Keywords: detection • bacterial disease • laser 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.