Available on-demand - EL07.09.14
Late News: Design of Novel Conjugated Polymers for Organic Electrochemical Transistor Biosensors
Maximilian Moser1,Sahika Inal2,Iain McCulloch1,2
University of Oxford1,King Abdullah University of Science and Technology2
Organic electrochemical transistors (OECTs) are bioelectronic devices that have gained significant attention recently, as they have shown excellent performances as biomolecule sensors, implantable brain signal recorders, neuromorphic computing elements and many other biomedical applications.1 Currently, the aqueous dispersion, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), has established itself as the OECT benchmark material, predominantly due to its commercial availability. PEDOT:PSS-based OECTs however display several disadvantages; namely i) their moderate OECT performances (quantified by the material-only dependent figure of merit μC*), ii) their depletion-mode of operation, iii) their inability to conduct electrons and iv) PEDOT:PSS’ highly complex structure preventing the formulation of structure-property relationships for future material design.2 Based on these limitations, this work focuses on synthesizing novel, cheap and solution processable glycol-ether (GE) functionalized conjugated polymers to advance OECT and hence biosensor performance, while concomitantly also establishing design-rules for the development of future OECT materials.
Several molecular design strategies are investigated. These range from tailoring the GE side chain length, to varying the nature of the aromatic building blocks and modifying the chemical composition of the solubilizing chains.3–5 Ultimately, we show how judicious optimization of the molecular structures, involving polymer energy level, polymer morphology and polymer electroactive swelling modulation, allows us to achieve unprecedented performance and stability benchmarks with μC* values of 522 F V-1 cm-1 s-1 (c.f. typically ~40 F V-1 cm-1 s-1 for the PEDOT:PSS benchmark)6 and devices retaining 98% of their initial current over 2 h of continuous electrochemical cycling.4 We then proceed to show how the combined performance and stability advances of our newly developed materials can be exploited in the fabrication of higher performing biosensors, including better sensitivity and lower power consumptions.
1. J. Rivnay, S. Inal, A. Salleo, R. M. Owens, M. Berggren and G. G. Malliaras, Nat. Rev. Mater., 2018, 3, 17086.
2. M. Moser, J. F. Ponder, A. Wadsworth, A. Giovannitti and I. McCulloch, Adv. Funct. Mater., 2019, 29, 1807033.
3. M. Moser, L. R. Savagian, A. Savva, M. Matta, J. F. Ponder, T. C. Hidalgo, D. Ohayon, R. Hallani, M. Reisjalali, A. Troisi, A. Wadsworth, J. R. Reynolds, S. Inal and I. McCulloch, Chem. Mater., 2020, 32, 6618.
4. M. Moser, T. C. Hidalgo, J. Surgailis, J. Gladisch, S. Ghosh, R. Sheelamanthula, Q. Thiburce, A. Giovannitti, A. Salleo, N. Gasparini, A. Wadsworth, I. Zozoulenko, M. Berggren, E. Stavrinidou, S. Inal and I. McCulloch, Adv. Mater., 2020, 32, 2002748.
5. M. Moser, A. Savva, K. Thorley, B. D. Paulsen, T. C. Hidalgo, D. Ohayon, H. Chen, A. Giovannitti, A. Marks, N. Gasparini, A. Wadsworth, J. Rivnay, S. Inal and I. McCulloch, Angew. Chem. Int. Ed., 2020, DOI: 10.1002/anie.202014078.
6. S. Inal, G. G. Malliaras and J. Rivnay, Nat. Commun., 2017, 8, 1767.