A stand-alone portable potentiostat with parallel channels for smart electrochemical analyses

In recent years portable potentiostats have increased in popularity allowing to perform electrochemical analyses outside the laboratories, moving them to home or point of care (PoC) environments. In this context, the idea of performing multiple acquisitions at the same time is particularly attractive to deal with replicates or with simultaneous multiple quantitative assessments of different analytes, shortening the time required for the analyses and/or increasing data reliability. Multiple parallel channels on a compact and wireless device can maximize the overall system usability. In this article, a multichannel Wi-Fi-based portable potentiostat is described. The device features four independent channels, which can be conditioned with different voltages. The device was designed to minimize the component count and the power consumption, obtaining 23.5 mW per channel. The system was electrically characterized, obtaining an excellent linearity ( $R^{2} =0.9999$ ), a maximum channel-to-channel mismatch of 1% when the maximum current range is selected, and a negligible crosstalk among the channels. Moreover, the multichannel potentiostat was tested in the real case scenario of a semiquantitative evaluation of the anti-tissue transglutaminase target antibodies in celiac disease. Two replicates of IgG and IgA were simultaneously acquired, showing a good capability of separating the positive and the negative samples, with a reduction of the acquisition time of 76% with respect to a single channel solution.