Multichannel, Portable and Low-Cost Source and Measure Unit Platform for the Continuous Characterization of Organic Electrochemical Transistor Biosensors

Organic Electrochemical Transistors (OECTs) have emerged as continuous monitoring sensors for in-vitro models. Source and Measure Units (SMUs) are typical instruments used to simultaneously control input and output signals on OECTs. Conventional SMUs are unsuitable for in-vitro application due to their limited channels count, large footprint and high cost. This work presents the design and the development of a multichannel, portable and cost-effective SMU platform for the continuous and long-term characterization of OECT biosensors. The hardware is based on an electronic board interfacing via customized connection to a six-OECT set-up, integrated in a standard culture plate and operated within a cell incubator. System functionality is managed by Arduino Nano microcontroller through ad-hoc software, enabling automated characterization of the OECTs. The platform characterization performance is evaluated by comparing the I – V characteristics and transient responses of the tested OECTs with those obtained by the commercial Keysight B2912A SMU. Long-term and continuous operation is verified by a 30 minutes-sampling, five days measurement. The assessed features of the platform and the achieved results suggest that the proposed prototype is more appropriate than conventional SMUs for OECT-based in-vitro biosensing. The presented solution has the potential to support biological research by offering an operator-independent and in-vitro compatible apparatus.