Surface functionalization of ion-sensitive floating-gate field-effect transistors with organic electronics

Qi Zhang, Himadri Majumdar, Matti Kaisti, Alok Prabhu, Ari Ivaska, Ronald Österbacka, Arifur Rahman, Kalle Levon

Research output: Contribution to journalArticleScientificpeer-review

40 Citations (Scopus)


Electrically conducting polymers are advantageous hybrid materials for microelectronic biosensors due to their high bandgap sensitivity, possibilities for nanoscale surface area formation, and well-developed surface bioconjugation strategies. In this paper, we investigated whether those organic conductors can also be used to functionalize ion-sensitive floating-gate field-effect transistors (ISFGFETs) designed to measure biological binding events. We first subjected our device to 100% relative humidity (RH) and proved its viability in such a humid environment. Subsequently, we drop-casted viscoelastic polyaniline emeraldine salt on pristine transistors to construct organo-functionalized devices. The modified ISFGFETs were stable in aqueous environments and sensitive to cationic polyethyleneimine. The directions of the ISFGFET threshold voltage (VT) shifts agree with the corresponding open-circuit potential variations for the same reaction and pH-sensitive behaviors of Al2O3 sensing layer on the transistor. Such organo-modified ISFGFET sensor arrays are promising alternatives to traditional conductive polymer-based potentiometric biosensors due to their signal amplification, high throughput, and scalability advantages.
Original languageUndefined/Unknown
Pages (from-to)1291–1298
JournalIEEE Transactions on Electron Devices
Issue number4
Publication statusPublished - 2015
MoE publication typeA1 Journal article-refereed

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