Design of a Low-Cost Portable Potentiostat for Amperometric Biosensors

This work shows the design of a low-cost, portable instrument for amperometric biosensors, which measures the faradaic currents originated by the electronic interchanges between a specific substance and a biological recognition system, present on an electrode and kept at an appropriate potential. The final objective is to obtain a direct relationship between those currents and the concentration of the substrate to be analyzed. This instrument may be used for sensors or cells with two or three electrodes in order to detect extremely low concentrations of a wide variety of substances. The instrument was evaluated comparing calibration curves from glucose, ethanol and cholesterol biosensors to those obtained from very expensive commercial equipment. Good linearity and sensibility, as well as low noise measurements were obtained. Moreover, thanks to its reduced size and low cost, this instrument can be used directly in field applications