In this presentation, I will present the benefits of using electrochemical methods applied to the field of micro nanofluidics, first on a theoretical level, then in terms of recent applications for the analysis of micro-RNAs (miRNAs). On a fundamental level, we will discuss recent advances concerning the theoretical expression of the diffusion-convection impedance for a microstrip electrode placed in a Poiseuille flow under microfluidic conditions [1]. The use of electrochemical impedance spectroscopy (EIS) highlights good agreement, in the entire swept frequency domain, between the expression of the modeled impedance and the experimental one. On the application level, we will see how controlling hydrodynamic and electrochemical parameters makes it possible to increase the efficiency of the collection rate during the hybridization of complementary sequences on microelectrodes [2],[3]. Finally, I will end with the development of HDE (Hyperthermy and Electrochemical Detection) technology based on the physical over-concentration of nucleic acid strands as a real alternative to PCR-type chemical amplification [4]. In short, HDE technology is in the philosophy of the ideal “laboratory-on-a-chip” integrating several complementary operations. Here, 3 modules are illustrated: capture, release and detection of nucleic acid strands (Figure 1)