Electrolyte Gated Organic Transistors can operate as powerful ultra-sensitive biosensors and efforts are currently devoted to devising strategies for reducing the contribution of hardly avoidable, non-specific interactions to their response, to ultimately harness selectivity in the detection process. We report a novel lab-on-a-chip device integrating a multigate Electrolyte Gated Organic Field-Effect Transistor (EGOFET) with a 6.5 µL microfluidics set up capable to provide an assessment of both the response reproducibility, by enabling measurement in triplicate, and of the device selectivity through the presence of an internal reference electrode. As proof-of-concept, we demonstrate the efficient operation of our pentacene based EGOFET sensing platform through the quantification of tumor necrosis factor alpha with a detection limit as low as 3 pM. Sensing of inflammatory cytokines, which also include TNF , is of the outmost importance for monitoring a large number of diseases. The multiplexable organic electronic lab-on-chip provides a statistically solid, reliable and selective response on microliters sample volumes on the minutes timescale, thus matching the relavant key-performance indicators required in point-of-care diagnostics.