Development of a submicrometer optical chemical sensor

Scott McCulloch; Deepak G. Uttamchandani

doi:10.1117/12.229173

3 January 1995 Development of a submicrometer optical chemical sensor

Scott McCulloch, Deepak G. Uttamchandani

Proceedings Volume 2631, Medical and Fiber Optic Sensors and Delivery Systems; (1995) https://doi.org/10.1117/12.229173
Event: BiOS Europe '95, 1995, Barcelona, Spain

Abstract

The near-field interaction between an optical aperture of sub-micrometer diameter and a sample surface can be exploited to spectroscopically probe a biological medium with a resolution unattainable with traditional far-field techniques. A simple, low-cost technique is described for producing a chemical sensor which is based on the principles of near-field optics, and preliminary results obtained using this device to measure pH are reported. Singlemode optical fibers are drawn into sub-micrometer optical fiber tips and then coated with aluminum, to form a subwavelength aperture. By using laser illumination through this aperture, samples can be studied with a resolution better than the wavelength of light. Sub- micrometer pH sensors have been prepared by incorporating the pH sensitive dye fluorescein into a silica based sol-gel glass which is then coated in the form of a thin film onto the fiber tip surface. These sensors were used to monitor the pH of buffer solutions inside micron-size holes in a polycarbonate membrane, and to probe the intracellular environment of mouse embryonic fibroblast cells. It was found that the pH response is reversible in the range 3 - 10. In addition the design potential of the sol-gel process for optimization of the sensor by careful control of the coating thickness is demonstrated.

Citation Download Citation

Scott McCulloch and Deepak G. Uttamchandani "Development of a submicrometer optical chemical sensor", Proc. SPIE 2631, Medical and Fiber Optic Sensors and Delivery Systems, (3 January 1995); https://doi.org/10.1117/12.229173

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available