Electrochemical Impedance Spectroscopy- based Biosensors

We developed an electrochemical impedance biosensor based on capacitance readout for the detection of biomolecules in small sample volumes. We demonstrated that our three-electrode setup is stable, reproducible, and suitable for real-time measurements. With this device we were able to follow in situ and in real time the process of DNA hybridization.  L. Ianeselli et al., Biosens. Bioelectronics 55 1 (2014).

		In this work we exploited electrochemical impedance spectroscopy to develop biosensor platforms for the detection of DNA hybridization. Two different configurations were tested: the first one consisting of two gold microelectrodes in a microfluidic channel, the second one a three-electrode, partially miniaturized electrochemical cell, consisting of two gold microelectrodes plus a macroscopic Ag/AgCl reference electrode. DNA hybridization was detected with both systems but the two-electrode setup showed a strong drift of the capacitance signal with time, that makes the use of this detector as a point-of-care medical diagnostic tool very problematic. The three-electrode setup, on the contrary, showed excellent time stability over more than 9 h, and is therefore the best candidate for a point-of-care device. Eventually we further showed the application of the three-electrode device to the study of DNA-hybridization in real time. The detector was able to successfully follow in-situ hybridization and can thus be used to collect valuable information about this very important mechanism.		Retrieve article Development of stable and reproducible biosensors based on electrochemical impedance spectroscopy: three-electrode vs two-electrode setup , Luca Ianeselli, Gianluca Grenci, Carlo Callegari, Massimo Tormen Loredana Casalis, Biosensors and Bioelectronics 55, 1 (2014)