  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%.
