  Field-Effect Transistors with graphene channels or GFETs are an interesting
alternative for the detection of analytes in biological fluids since the
electrical behavior of the channel changes when exposed to a sample (among
other detection strategies). In this work a preliminary characterization is
made in terms of the resistance of the channel for a commercial device that has
GFETs of 1 and 3 channels for cases of dry and wet gate at atmospheric
pressure. The channel resistance was obtained by sweeping the drain-source
voltage from -1 to +1V and measuring the drain current in a test station
developed for this purpose, for gate cases with and without a PBS 0.001X
reference solution. The ohmic response of the channel is linear current with
respect to voltage, being greater resistance in the case of wet gate. An
increase in resistance with respect to voltage was observed that it is
important to review. It was possible to make the ohmic characterization of the
channel and a series of recommendations are suggested to continue this
research.
