• DOI:10.1039/c4an00714j
• Corpus ID: 22972480

Selective ion-sensing with membrane-functionalized electrolyte-gated carbon nanotube field-effect transistors.

@article{Melzer2014SelectiveIW,
  title={Selective ion-sensing with membrane-functionalized electrolyte-gated carbon nanotube field-effect transistors.},
  author={Katharina Melzer and A. M. M{\"u}nzer and Ewa Jaworska and Krzysztof Maksymiuk and Agata Michalska and Giuseppe Scarpa},
  journal={The Analyst},
  year={2014},
  volume={139 19},
  pages={
          4947-54
        }
}

• K. Melzer, A. M. Münzer, +3 authors G. Scarpa
• Published 26 August 2014
• Chemistry
• The Analyst

In this work the ion-selective response of an electrolyte-gated carbon-nanotube field-effect transistor (CNT-FET) towards K(+), Ca(2+) and Cl(-) in the biologically relevant concentration range from 10(-1) M to 10(-6) M is demonstrated. The ion-selective response is achieved by modifying the gate-electrode of an electrolyte-gated CNT-FET with ion-selective membranes, which are selective towards the respective target analyte ions. The selectivity, assured by the ion-selective poly(vinyl chloride) based membrane, allows the successful application of the herein proposed K(+)-selective CNT-FET to detect changes in the K(+) activity in the μM range even in solutions containing different ionic backgrounds. The sensing mechanism relies on a superposition of both an ion-sensitive response of the CNT-network as well as a change of the effective gate potential present at the semiconducting channel due to a selective and ion activity-dependent response of the membrane towards different types of ions. Moreover, the combination of a CNT-FET as a transducing element gated with an ion-selective coated-wire electrode offers the possibility to miniaturize the already well-established conventional ion-selective electrode setup. This approach represents a valuable strategy for the realization of portable, multi-purpose and low-cost biosensing devices.