Invited Speaker

Abstract: Organic thin-film transistors (OTFTs) have attractive features including lightweight, mechanical flexibility, compact integration. Utilizing such features, we have employed extended gate-type OTFTs functionalized by bio- or artificial materials toward new sensing platforms [1-3]. Due to molecular recognition phenomena, the electrical properties (e.g. drain current, threshold voltage, and transfer or output characteristics) of the OTFT devices vary upon by the addition of the analyte on the extended-gate. Based on the working principle, we have successfully detected organic/inorganic cations, anions, nonions and biomacromolecules [1]. It should be noted that the OTFTs offer simple analytical methods without pre-treatments and complicated procedures. As representatives, we herein demonstrate our successful detection of lactate and immunoglobulins by the OTFTs (Fig. 1A, B) [2,3]. Furthermore, the OTFTs can be integrated with microfluidic systems [4] for real-time monitoring in biological fluids. We realized the real-time monitoring of changes in glucose (Glc) concentrations (Fig.1C) [4]. Thus, the OTFTs are suitable as sensor devices for the analyses of biological molecules. Overall, our approach would be reliable sensing platforms in practical analyses in the fields of biochemistry and clinical chemistry.

Fig.1 Photograph of the fabricated OTFT. (A) Left: Schematic illustration of OTFT enzyme sensor for lactate. Right: Time-course of drain current with increasing concentration of lactate. (B) Left: Immobilization of anti-IgG antibody on the extended-gate electrode. Right: Transfer characteristics (IDS–VGS) of the OTFT upon titration with IgG in a D-PBS solution with 0.1 wt% bovine serum albumin (BSA). Inset: [IgG] = 0–100 μg/mL. (C) Left: Top view of the OTFT integrated with the microfluidic system for glucose detection. Middle: Side view of the integrated device. Right: Time-course of the drain current with randomly changing concentration of Glc (pseudo glucose consumption by living cells).

Keywords: Organic Thin-Film Transistor, Molecular Recognition, Microfluidic System, Lactate, Immunoglobulin, Glucose
References: [1] T. Minami et al., ACS Sens., 2019, 4, 2571 (Front Cover); [2] T. Minami et al., Anal. Sci., 2019, 35, 103; [3] T. Minami et al., Appl. Phys. Lett., 2014, 104, 243703 (The most accessed article in 2014-2016); [4] T. Minami et al., ChemElectroChem, 2020, 7, 1332 (Cover Feature)

Biography: Tsuyoshi Minami received his PhD (Eng) from Tokyo Metropolitan University (Japan) in 2011. During his PhD studies he worked at University of Bath (UK) on collaborative projects. Between 2011 and 2013 he was a Postdoctoral Research Associate at Bowling Green State University (US). In 2013 he was appointed as a Research Assistant Professor at the same University. Then he moved to Yamagata University (Japan) as an Assistant Professor in 2014. He was appointed as a Lecturer at The University of Tokyo in 2016, and then he has been an Associate Professor since 2019 at the same University.