Fabrication and characterization of a surface plasmon resonance based fiber-optic sensor for bittering component—Naringin

The fabrication and characterization of a surface plasmon resonance (SPR) based fiber-optic sensor to determine the amount of naringin, which causes bittering effect in citrus fruit juices, have been reported. The sensing region has been fabricated by coating about 1 cm length of the unclad core with silver. To sense naringin, the enzyme, naringinase, has been immobilized over the metallic surface. The spectral interrogation method has been used to characterize the sensor. It has been observed that the SPR wavelength increases with an increase in the concentration of naringin. In addition, the sensitivity, reproducibility and the signal to noise ratio (SNR) of the sensor have been studied. It has been found that the sensitivity increases with an increase in the concentration of naringin, while the reverse is the case for SNR. The fiber-optic SPR sensing probe reported can be repeatedly used. Further, it can be used for remote and in situ monitoring of the naringin concentration.