Detection of ethanol in water by electrical impedance spectroscopy and resonant perturbation method

Development of highly sensitive, portable and low-cost sensors for the evaluation of ethanol content in liquid is particularly important in several process monitoring, from food to pharmaceutical industry. In this respect, here we report on the design, fabrication and performances of two simple electrical devices, namely interdigitated (ID) electrodes and complementary double split ring resonator (CDSRR), for the detection of ethanol in water though impedance and perturbation resonance methods, respectively. Both sensors resulted to be efficient for detection of low amount of ethanol in water, in particular EIS gives possibility to perform broadband evaluation of ethanol concentration in solution, and the employment of resonant cavities allows to achieve very low limit of detection of 0.2v/v%.