In this paper a pH monitoring system is demonstrated by utilizing wavelength modulated fiber optic techniques. A
stimulus responsive hydrogel which exhibits a volume change with the change of pH is utilized to render a strain on Fiber
Bragg grating (FBG). The gel is synthesized from the blends of Poly (vinyl alcohol)/Poly (acrylic acid). The induced
strain causes a FBG peak shift that can be used as a measure of pH change. The proposed sensing system exhibits a good
linearity in acidic pH range of 3 to 7 with a sensitivity of 250 pm/pH. Besides that it is very cost effective, bio degradable
and also possess repeatability.
The present article proposes carcinogenic Chromium (VI) metal ion sensor by a hydrogel coated etched Fiber Bragg
grating (FBG). Hydrogel synthesized from the blends of 3-arylamidopropyltrimethylammoniumchloride (ATAC) which
is stimulus responsive to chromium ions suffers a volume change in different Cr solutions. Upon exposure to various
concentrations of Cr (VI) ion solutions, FBG peak is shifted due to the mechanical strain induced by the stimulus swelling
property of the hydrogel. The peak shift is correlated with the concentration of the Cr (VI) metal ion. Thus a Chemo-mechanical-
optical sensing approach for the detection of Cr (VI) is studied. Trace amounts of Chromium (VI) ion as low
as 10 ppb can be estimated by the method. The resolution of the sensor system is found to be 0.05 ppb.
The cladded U-bent plastic optical fiber (POF) probes with single, triple and quintuple U-bent regions investigated under this study show a RI sensitivity of 2.7, 3.7 and 2.3 absorbance units/RI units respectively. The highest sensitivity obtained here is more than 50% of decladded single U-bent POF probes, however with superior chemical resistance.
The present article discusses a cost effective technique for the detection and quantification of copper ion by using localized surface Plasmon resonance (LSPR) based fiber optic technique. For the purpose, a small portion of a plastic optical fiber is functionalized with gold nanoparticles which are modified with 4-mercapto benzoic acid (4-MBA). The proposed is very successful in the detection of Cu2+ even in trace levels (ppb) in a wide range of real time samples. The results are comparable with the existing detection techniques.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.