Portable electrolyte-gated organic field-effect transistor platform for enabling ultrasensitive and rapid detection...

Viral hepatitis, particularly hepatitis B (HB) and hepatitis C (HC), has remained a major global health concern for decades due to its high infectivity and the liver damage it causes, which can lead to severe long-term complications. Thus, the development of diagnostic tools that enable rapid, cost-effective, and user-friendly detection of hepatitis infections is crucial. Here, we report label-free immunosensors for the detection of HB/HC biomarkers (Hepatitis B surface antigen, HBsAg, and Hepatitis C core antigen, HCcAg) using conventional electrolyte-gated organic field effect transistors (EGOFETs) as electrical transducers by modifying the gate contact with suitable antibodies. To enhance portability and enable point-of-care (PoC) operation, the EGOFETs were subsequently integrated into a lateral flow assay architecture (LF-EGOFET), where the antibodies are immobilized within a nitrocellulose membrane in contact with a coplanar gate electrode. The devices were evaluated as PoC diagnostic tests in buffer solutions and diluted artificial saliva, demonstrating high sensitivity, selectivity, and accuracy, with limits of detection (LoD) in the femtomolar range. Notably, the LF-EGOFET platform achieves a LoD over three orders of magnitude lower than those of commercial hepatitis lateral flow assays, while avoiding the use of labels and enabling the identification of discrete concentration ranges.