Real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentration by electromagnetic sensing

•Proposed sensor has a wide dynamic range, high linearity and compact size.•Real-time measurement and low-cost, which is particularly suitable for use as a sugar sensor technology in the future.•Method detection is simple and without sample preparation.

Magnetic sensing at microwave frequencies for real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentrations is reported. The sensing element was designed based on a coplanar waveguide (CPW) loaded with a split ring resonator (SRR), which was fabricated on a DiClad 880 substrate with a thickness of 1.6 mm and relative permittivity (εr) of 2.2. The magnetic sensor was connected to a Vector Network Analyzer (VNA) and the electromagnetic interaction between the samples and sensor was analyzed. The magnitude of the transmission coefficient (S21) was used as an indicator to detect the solution sample concentrations ranging from 0.04 to 0.20 g/ml. The experimental results confirmed that the developed system using microwaves for the real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentrations gave unique results for each solution type and concentration. Moreover, the proposed sensor has a wide dynamic range, high linearity, fast operation and low-cost.