Optical fiber pH sensors functionalized with a gold nanoparticle (AuNP)/porous silica film were developed. The transmission of light through the fiber is affected by the change in the refractive index of the porous silica-based nanocomposite coated film as ionic species are concentrated into the coating film when the silica surface becomes negatively charged with increasing pH. To investigate the dependence of the response on the ionic species in solution, we report the optical response of Au/silica film coated fibers in a variety of salt solutions. The response is indeed sensitive to different ionic species in solution. The details of the response are likely also sensitive to the microstructure of the porous silica-based sensing layer.

Date Published: 17 May 2016
PDF: 8 pages
Proc. SPIE 9836, Micro- and Nanotechnology Sensors, Systems, and Applications VIII, 98360I (17 May 2016); doi: 10.1117/12.2224959

Published in SPIE Proceedings Vol. 9836:
Micro- and Nanotechnology Sensors, Systems, and Applications VIII
Thomas George; Achyut K. Dutta; M. Saif Islam, Editor(s)