A highly selective LSPR biosensor for the detection of taurine realized on optical fiber substrate and gold nanoparticles

Abstract In the current study, we report an enzyme based fiber optic biosensor utilizing the localized surface plasmon resonance (LSPR) of gold nanoparticles for the detection of taurine in the concentration range of 0–1 mM. For probe fabrication, gold nano-particles are decorated on an unclad portion of multimode optical fiber, and taurine dioxygenase enzyme is immobilized over them. The presence of taurine and its co-reactants alpha-ketoglutarate and oxygen in the vicinity of the probe activates the immobilized enzyme which elicits the chemical reaction that gets manifested in the form of refractive index change in the surrounding of gold nanoparticles. This changes the absorbance spectrum of the nanoparticles recorded at the output end of the fiber probe. The absorbance spectrum changes in terms of absorbance and peak absorbance wavelength. A change of 0.0115 in absorbance value is obtained for the change in taurine concentration from 0 to 1 mM. The limit of detection and the sensitivity of the sensor are found to be 53 µM and 0.0190 AU/mM, respectively. The sensor response is found to be stable and selective along with good repeatability. Being fabricated on optical fiber substrate, the sensor possesses the inherent advantages like online and remote monitoring of taurine along with immunity to electromagnetic noise. Moreover, the reported sensor has simple operation and is low in cost.