Sensors for Continuous Measuring of Sucrose Solutions Using Surface Plasmon Resonance

Abstract

We propose two new sensors based on surface plasmon resonance (SPR) and optical fibers to determine the concentration of sucrose in products such as beverages, honey, condensed milk, etc., in real-time during the fabrication process or when the product has been manufactured. The sensors have been made with a hemispherical prism, a layer of MgF2, and another of Ag or Al with the Kretschmann configuration, and they are modulated in intensity. We have optimized these sensors from the modeling of reflectance curves. We have carried out a numerical simulation with these sensors to show how they can detect small changes in the refractive index depending on the concentration of sucrose where the device is immersed. The maximum sensitivity of the sensors is 11.9 RIU−1 and 5.7 RIU−1, the resolutions 1.7 × 10−4 RIU and 7.9 × 10−4 RIU, and the detection limits between 0-78Brix. Moreover, the sensors have an alarm system that is triggered when the sucrose concentration is insufficient or excessive. Data can also be sent in real-time to a remote place.