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Microfabricated Ion‐Selective Transistors with Fast and Super‐Nernstian Response
Author(s) -
Han Sanggil,
Yamamoto Shunsuke,
Polyravas Anastasios G.,
Malliaras George G.
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202004790
Subject(s) - materials science , miniaturization , transistor , ion , optoelectronics , nanotechnology , transconductance , electrolyte , membrane , bioelectronics , electrode , microfabrication , ion channel , sensitivity (control systems) , biosensor , fabrication , electrical engineering , electronic engineering , voltage , chemistry , medicine , biochemistry , alternative medicine , receptor , organic chemistry , pathology , engineering
Transistor‐based ion sensors have evolved significantly, but the best‐performing ones rely on a liquid electrolyte as an internal ion reservoir between the ion‐selective membrane and the channel. This liquid reservoir makes sensor miniaturization difficult and leads to devices that are bulky and have limited mechanical flexibility, which is holding back the development of high‐performance wearable/implantable ion sensors. This work demonstrates microfabricated ion‐selective organic electrochemical transistors (OECTs) with a transconductance of 4 mS, in which a thin polyelectrolyte film with mobile sodium ions replaces the liquid reservoir. These devices are capable of selective detection of various ions with a fast response time (≈1 s), a super‐Nernstian sensitivity (85 mV dec −1 ), and a high current sensitivity (224 µA dec −1 ), comparing favorably to other ion sensors based on traditional and emerging materials. Furthermore, the ion‐selective OECTs are stable with highly reproducible sensitivity even after 5 months. These characteristics pave the way for new applications in implantable and wearable electronics.