A large-area processable ink-jet-printed poly(3-hexylthiophene) electrolyte-gated field-effect transistor, designed for bioelectronic applications, is proven to be stable for one week of continuous operation.

The timely diagnosis of cystic pancreatic cancer precursors is of utmost importance to improve patients’ low survival rate. Fine‐needle aspiration cytology is endowed with low diagnostic sensitivity, while more effective is the assay of markers, such as a mutated KRAS, in the cyst fluids. Next‐generation sequencing, detecting down to a single copy of a genomic marker, enables early diagnosis but the diagnostic sensitivity of high‐grade cysts, likely to become malignant, is low. Assaying both mutated KRAS and MUC1 protein markers can improve diagnostic accuracy. Their detection in blood would also be minimally invasive. Here, the mucinous lesions markers, KRAS and MUC1, are both successfully assayed in blood serum at the physical limit with the label‐free “Single‐Molecule assay with a large Transistor—SiMoT.” This is a compelling proof of principle that the SiMoT platform holds high potential to enable a timely, minimally invasive, and accurate diagnosis of pancreatic cancer precursor cysts.