pH Value Detection with CLPFG Sensor

Abstract

Detection of pH value plays an important role in many fields; the precise measurement of pH value is very useful in Living systems, Chemistry and Biochemistry. The purpose of this paper is to measure pH value in solution by using Corrugated Long Period Fiber Grating (CLPFG). The CLPFG element is highly sensitive to refractive index changes, and with appropriate design geometry; a variety of target molecules can then be detected. Optical fiber Corrugated Long Period Gratings are designed to act as spectral loss elements that couple with a discrete wavelength out of the optical fiber as a function of the surrounding refractive index. By applying special coating that change refractive index with absorption of target molecules to the CLPFG surface, it became a transducer for chemical measurement. In this paper, it has shown the incorporation of Polyvinyl Alcohol and Polycyclic Acid (PVA-PAA) with Corrugated Long Period Gratings for the development of a fiber optic-based pH sensor with the detection of pH range from 3 to 6. Optical fiber-based pH sensors offer numerous advantages in wastewater monitoring, remote blood diagnostics, bioremediation, as well as chemical and food processing.

Fiber-Optic Chemical Sensors and Biosensors (2013–2015)

“…The corrugated long period fiber grating element is highly sensitive to RI. By coating it with a pH-sensitive material [poly­(vinyl alcohol) and poly­(acryclic acid); PVA–PAA], a fiber-optic pH sensor is obtained that can detect pH’s in the range of 3–6 with a resolution of 0.02 pH units . The same PVA–PAA coating was applied to develop an interferometric pH sensor …”

“…By coating it with a pH-sensitive material [poly(vinyl alcohol) and poly(acryclic acid); PVA−PAA], a fiber-optic pH sensor is obtained that can detect pH's in the range of 3−6 with a resolution of 0.02 pH units. 150 The same PVA−PAA coating was applied to develop an interferometric pH sensor. 151 By integrating the fiber-optical sensing technique with wireless data transmitting technology, a hybrid wireless sensor network was established.…”

Chemically modified optical fibers in advanced technology: An overview

“…A fiber-optic pH sensor coated with a pH-sensitive material [poly-(vinyl alcohol) and poly-(acrylic acid); PVA-PAA] has been prepared to detect pH's in the range of 3-6 with a resolution of 0.02 pH units [187]. An adsorption-based evanescent wave FOs was constructed by immobilizing the pH sensitive indicator bromophenol blue in an ormosil hybrid material [188]. The sensor can reversibly determine pH's in the range from 3 to 9, but with a poor precision (0.2 pH units).…”

Hydrogel-integrated plasmonic nanostructures on optical fiber facet for remote and real-time pH sensing

“…9 Fiber-optic pH sensors usually use functional sensing materials on fiber sidewall to perform pH sensing functions. 10,11 However, this kind of fiber probes are brittle and not miniature in the longitudinal direction. These problems can be resolved when functional layer is patterned on the facet of optical fiber.…”