The Development of a Highly Sensitive Fiber-Optic Oxygen Sensor

Abstract: This paper presents a highly sensitive fiber-optic oxygen sensor. The sensor was fabricated using palladium (II) meso-tetrakis (pentafluorophenyl) porphyrin (PdTFPP) and porous silica nanoparticles embedded in a tetraethylorthosilane (TEOS)/n-octyl-triethoxysilane (Octyl-triEOS) composite xerogel present as a coating on the end of the fiber. Sensitivity is quantified in terms of the ratio IN2/IO2, where IN2 and IO2 represent the intensity of fluorescence detected in a pure nitrogen or pure oxygen environment. The experimental results reveal that this PdTFPP-doped oxygen sensor with porous silica nanoparticles has a sensitivity of IN2/I100O2 = 386. The results also show that this sensor has higher sensitivity than an oxygen sensor based on Pd(II) complex immobilized in a sol-gel matrix. Furthermore, the optical oxygen sensor yields a linear Stern–Volmer plot. The proposed optical sensor has the advantages of easy fabrication, low cost, and high sensitivity to oxygen.