Reconsideration of the dielectric properties response of concentration dependence of aqueous urea solution at the microwave frequency

In this paper, we investigate the dielectric properties of aqueous urea solution over the frequency range 200 MHz–20 GHz. We reveal the single nature of urea–water cooperative interaction and draw a profile of the overview that urea–water cooperative interaction plays a dominating role in the aqueous urea solution system using Cole–Cole analysis. The self-diffusion coefficient is related to the concentration of the urea aqueous solution. The decay of the effective number of water molecules bound to the urea molecules with its concentration and the urea perturb the water structure beyond the first hydration shell, which is confirmed in the aqueous urea solution system. And the relation between τ and α may be utilised widely to measure the urea concentration for a microwave biosensor technique.