Palestrante
Descrição
The biggest challenge in bioelectronics is to produce devices that are able to transduce ionic fluxes from living system into electronic signals, with good signal-to-noise ratio. The device of choice that has shown great success as mixed ionic-electronic translator is the organic electrochemical transistor (OECT). (1) Such device support both ionic and electronic transport with similar efficiency due to the morphological characteristics of organic materials. Besides that, OECTs can be made flexible, are bio-compatible, operates with low-voltages and has relatively fast response. However, most of the biological application of OECTs as biosensors requires some sort of ionic selectivity. Currently, selection of specific ionic species is done by functionalizing the OECT with selectivity membranes. However, the process is time consuming, expensive and not always effective. To overcome this issue, we have studied the electrical, electrochemical as well as swelling response of OECT when it operates in contact with electrolyte with different ions. Our results indicate that the ionic specie in the electrolyte has a strongly influence in the OECT performance. Both volumetric capacitance (C) and time response (τ) were strongly influenced by the type of ionic specie used. To put it into perspective, C has increased more the 40 % when using MgCl2 as opposed to NH4Cl. Our results are leading to a more depth understanding of the interaction ion-polymer matrixes and we are currently working on new methodology of data processing that allow the separation of signal contribution of different ionic species in the same electrolyte. Besides, our results can be further used as guidelines to build more efficient devices, simply by choosing the correct ionic specie to be sensed.
Referências
1 RIVNAY, J. et al. High-performance transistors for bioelectronics through tuning of channel thickness. Science Advances, v. 1, n. 4, p. e1400251-1-e1400251-5, May 2015.
| Subárea | Física da Matéria Condensada |
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