Flexible Electrolyte-Gated Ion-Selective Sensors Based on Carbon Nanotube Networks

Abstract

We demonstrate the ion-selective response of an electrolyte-gated carbon nanotube network based field-effect transistor fabricated on a flexible polyimide substrate. Selective response towards the two prominent second messengers for cellcell communication, namely K + and Ca 2+ is demonstrated by modifying the carbon nanotube network with different polymeric ion-selective membranes. The sensing mechanism relies on the transduction of the ionic signal in an electrical one due to an ionactivity dependent change of the membrane potential at the membrane/electrolyte interface, which leads to a change in the effective gate-potential affecting the charge transport in the semiconducting channel. These sensors can be successfully used to selectively detect concentrations of primary ions down to a concentration in the μM range even in solutions with a highly concentrated background of interfering ions. Our approach allows the realization of low-cost, flexible, portable and multipurpose biosensing devices.Index Terms-carbon nanotubes, electrolyte-gated field-effect transistor, flexible, ion-selective membrane, ion-sensitive fieldeffect transistor

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Acidic Ionic Liquids as Sustainable Approach of Cellulose and Lignocellulosic Biomass Conversion without Additional Catalysts

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Recent Advances in Flexible Field‐Effect Transistors toward Wearable Sensors

“…Reproduced with permission. [219] Copyright 2015, IEEE. h) Schematic illustration of RuO x FET sensor, with the functionalized 4-CPBA glucose sensing layer.…”

“…[11,160,[208][209][210] F-FET-based biochemical sensors could provide in situ monitoring of the sweat compositions in a noninvasive way. [211] Considering the complexity of sweat compositions, numerous sensors have been reported toward different ingredients, including pH sensors, [47,147,210,[212][213][214][215][216][217] ion sensors, [47,147,[218][219][220][221][222][223] glucose sensors, [21,45,48,159,[224][225][226] lactate sensors, [227] etc. Based on WO 3 NP, Santos et al [212] reported a representative F-FET-based pH sensor for in vivo applications (Figure 12e).…”