The present invention concerns a method of detecting macroions in a liquid medium contained in a space, the method including: a) submitting the liquid medium to a stimulating electrical field to induce formation of aggregates of macroions, the formed aggregates of macroions preferably not including any additional labeling agent, and b) measuring, in a detection zone of the space, spatial and/or temporal fluctuations within the liquid medium of at least one variable depending on the concentration of the macroions in the liquid medium, and c) determining, based on these fluctuations, the presence of the macroions, step c) preferably including processing by a time-dependent or space dependent analysis, more preferably by wavelet analysis, or by autocorrelation the fluctuations measured at step b).