Development of ligand functionalized fiber optic sensor for nickel ion detection
Date of Issue2016-05-25
School of Chemical and Biomedical Engineering
The elevated levels of heavy metal contaminants in the environment as a result of anthropogenic based activities pose a significant threat to human health. This has prompted an urgent need for the development of a simple, fast and cost-effective sensing technique for the detection of heavy metal ions in the environment. In this study, a novel ligand functionalized fiber optic sensor consisting of a Single Mode Fiber (SMF) and a No Core Fiber (NCF) is proposed and demonstrated for Nickel ion detection. In order to evaluate the sensitivity of the fabricated sensor, a refractive index test was conducted. From the results obtained, it was observed that the interference dips shifted towards longer wavelengths as the RI of the surrounding medium was increased thus indicating that the sensor was sensitive to changes in RI. The surface of the sensor was then functionalized by the ligand Meso-Tetra (4- carboxyphenyl) porphine via the silane-coupling agent Triethoxysilane to allow the Ni2+ ions to be captured onto the surface of the sensor by the ligand receptors. Upon subjecting the functionalized sensor to different nickel ion concentrations, the interference dips in the reflectance spectrum observed to shift towards longer wavelengths with increasing nickel ion concentration. The sensitivity of the sensor was observed to be 121.03 nm/mM with R2 value = 0.8411 in the nickel concentration range up to 0.02mM, thereby providing evidence that the functionalized sensor demonstrated good sensitivity to nickel ions and therefore is a suitable alternative method for detecting the heavy metal nickel in water.
Final Year Project (FYP)
Nanyang Technological University