Non-invasive Healthcare Analytical Platform Based on Organic Electrochemical Transistors

Non-invasive bioelectronics, especially organic electrochemical transistors (OECTs), have drawn extensive attentions of academical and medical communities by virtue of their efficient bio-electronic interfacing, water-involved ionic transport, excellent ionic-electronic coupling, ultralow power consumption, wide detectable range, and outstanding detection sensitivity. Designable structure diversity, low-temperature solution processability, facile bio/chemical functionalization, and excellent biocompatibility of organic mixed ionic-electronic conductors (OMIECs) render OECTs particularly suitable for non-invasive or minimally invasive healthcare analytical platform. Here, we comprehensively review recent advances of the non-invasive analytical healthcare applications based on OECTs, especially on the detection of biomarkers or metabolites in the excretory biofluids, as well as the recording of electrophysiological signals. A brief introduction of OECT and its comparison with other organic thin-film transistors upon device configuration and working mechanism are firstly discussed. State-of-the-art non-invasive OECT-based biosensors are summarized on their detection of ionic and molecular biomarkers, following with circuit design strategies of OECTs for real-time and in-situ electrophysiological recording from skin surface. In conclusion, remaining barriers and future challenges of non-invasive OECT-based bioelectronics towards lower detection limit, more accurate quantitative relationship between analyte concentrations and measured parameters, more intimate device-tissue interface, and long-term operation stability are deeply analyzed with a critical outlook.