  This paper presents an attractive method towards sensing and quantifying the
concentration of dielectric particles suspended in a highly conductive medium.
Fast electrical impedance spectroscopy (EIS) measurements were performed, based
on an electrochemical setup and a non-parametric unbiased estimator. The
impedance data are then mapped from the frequency domain to a time constant
domain via the distribution of relaxation times (DRT) model. It is shown that
application of DRT can systematically give a distribution function which is
directly related with the concentration of micro-colloid samples. As a result,
the samples were characterized by high sensitivity and resolution.
