Electrolyte-Gated Field Effect Transistors in Biological Sensing: A Survey of Electrolytes

Wang, Guan Ying; Lian, Keryn; Chu, Ta−Ya

doi:10.1109/jeds.2021.3082420

Cited by 25 publications

(23 citation statements)

References 120 publications

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“…Aqueous electrolytes in the liquid state allow the receptor to be functionalized in a dense layer directly on the gate or channel of the transistor to obtain higher sensitivities. Aqueous electrolytes provide low electrical conductivity, increase ionic conductivity, and increase biocompatibility [ 48 ]. Avci’s team developed the EGFET pH micro-sensor for fast pH detection; after measuring pH 5 to pH 12, the response was accurate.…”

Section: Resultsmentioning

confidence: 99%

The Characteristics Analysis of a Microfluid-Based EGFET Biosensor with On-Chip Sensing Film for Lactic Acid Detection

Kuo

Chang

Lai

et al. 2022

Sensors

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In this research, a microfluid-based extended gate field-effect transistor (EGFET) biosensor with an on-chip sensing window (OCSW) was fabricated. The detection window was composed of six metal layers, and a ruthenium dioxide (RuO2) film was spattered on the surface and functionalized with lactase to detect lactic acid (LA). To detect LA in a more diversified way, a microfluidic system was integrated with the biosensor. Moreover, a special package was used to seal the sensing window and microfluidic tube and insulate it from other parts to prevent water molecule invasion and chip damage. The sensitivity analysis of the EGFET biosensor was studied by a semiconductor parameter analyzer (SPA). The static and dynamic measurements of the EGFET with sensing windows on a chip were analyzed. The sensing characteristics of the EGFET biosensor were verified by the experimental results. The proposed biosensor is suitable for wearable applications due to the advantages of its low weight, low voltage, and simple manufacturing process.

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Section: Resultsmentioning

confidence: 99%

The Characteristics Analysis of a Microfluid-Based EGFET Biosensor with On-Chip Sensing Film for Lactic Acid Detection

Kuo

Chang

Lai

et al. 2022

Sensors

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“…Although leaching is an extreme situation, the most common sources of EGT instabilities include the electrochemical redox reactions between the EGT materials, such as those used for the gate, channel, source and drain, and the electrolyte or the biolayer embedded in the EGT; morphological changes of the channel material due to hydrophobic-hydrophilic interactions with the electrolyte; and water diffusion and ion doping during long-term operation 289,290 . EGT degradation can also take place in ambient conditions 117,134,[291][292][293][294][295][296][297] . This path of degradation could be a result of morphological and/or chemical interactions on the surface semiconductors or in the whole bulk of the EGT channel 116,117,291,296,298 .…”

Section: Limitations and Optimizationsmentioning

confidence: 99%

Electrolyte-gated transistors for enhanced performance bioelectronics

Torricelli

Adrahtas

Bao

et al. 2021

Nat Rev Methods Primers

260

237

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Bioelectronics enables the study of the aqueous media that host soft tissues and interfaces for their proper function, as well as of the connections between various cells and/or organs, which communicate by exchanging specific ions and biomolecules 1 . The fundamental properties of the biological systems set the requirements of the electronics counterpart. Electrolyte-gated transistors (EGTs) have emerged as important building blocks for enhanced bioelectronics because they are stable in an aqueous environment, operate at low voltages and can transduce and amplify biological signals into electronic signals [2][3][4][5] .EGTs are three-terminal devices where the conductivity of a semiconducting material connected to two electrodes, classified as the source and the drain, is modulated by a third electrode known as the gate. In a basic EGT, the gate electrode and the semiconducting channel are in direct contact with the electrolyte. A voltage V G and V D is applied at the gate and drain electrode, respectively (Fig. 1a). V G and V D are referenced to the source voltage, which is typically set to ground, V S = 0 V. The polarity and magnitude of the voltage applied to the gate electrode result in a drift of cations or anions from the electrolyte to the semiconducting channel. The ionic charges can enhance or deplete the electronic charges residing in the semiconductor channel. This ionicelectronic modulation gives rise to a large variation of the channel conductivity that, in turn, manifests in a large modulation of the electronic source to drain current flowing through the transistor channel. Upon application of the gate, source and drain voltages, ions drift into the electrolyte and accumulate at the gate and semiconductor. The sign of the gate voltage controls the charge type of these ions (cations or anions), whereas its magnitude controls their density. For example, when a positive gate voltage is applied, the anion concentration increases at the gate and the cation concentration increases at the semiconducting channel. The sub-nanometre scale dimension of the ions interacting with the gate and channel materials results in a large electrostatic interaction at the gate/electrolyte and electrolyte/channel interfaces, which yields the low-voltage operation of EGTs that can range from a few volts to even less than 1 V, depending on the specific materials used. The low-voltage operation is critically important for electrophysiology and in the case of a large variety of biosensors. In addition, in contrast to the conventional thin-film field-effect transistors, in EGTs the gate is not required to be positioned in front of the channel as the charge modulation is due to the accumulation or depletion of ions transported within

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“…Electrolyte gated organic transistors (EGOT) are emerging as a fascinating platform for biological sensing in aqueous medium. 4 However, some applications require solid-state gating materials and operation with high switching speeds such as memory devices and logic-based circuits. Electrolyte gated transistors suffer from slow switching speeds due to the electrochemical doping and undoping of the semiconductor layer.…”

Section: ■ Introductionmentioning

confidence: 99%

“…From wearable electronics to low-cost point of care sensors, , organic thin film transistors (OTFTs) are integral to the function of these devices. Electrolyte gated organic transistors (EGOT) are emerging as a fascinating platform for biological sensing in aqueous medium . However, some applications require solid-state gating materials and operation with high switching speeds such as memory devices and logic-based circuits.…”

Section: Introductionmentioning

confidence: 99%

Poly(ionic liquid) Gating Materials for High-Performance Organic Thin-Film Transistors: The Role of Block Copolymer Self-Assembly at the Semiconductor Interface

Brixi

Radford

Tousignant

et al. 2022

ACS Appl. Mater. Interfaces

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The widespread realization of wearable electronics requires printable active materials capable of operating at low voltages. Polymerized ionic liquid (PIL) block copolymers exhibit a thickness-independent double-layer capacitance that makes them a promising gating medium for the development of organic thin-film transistors (OTFTs) with low operating voltages and high switching speed. PIL block copolymer structure and self-assembly can influence ion conductivity and the resulting OTFT performance. In an OTFT, self-assembly of the PIL gate on the semiconducting polymer may differ from bulk self-assembly, which would directly influence electrical double-layer formation. To this end, we used poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} (P(NDI2OD-T2)) as a model semiconductor for our OTFTs, on which our PILs exhibited self-assembly. In this study, we explore this critical interface by grazing-incidence small-angle X-ray scattering (GISAXS) and atomic force microscopy (AFM) of P(NDI2OD-T2) and a series of poly(styrene)-b-poly(1-(4-vinylbenzyl)-3-butylimidazolium-random-poly(ethylene glycol) methyl ether methacrylate) (poly(S)-b-poly(VBBI+[X]-r-PEGMA)) block copolymers with varying PEGMA/VBBI+ ratios and three different mobile anions (where X = TFSI–, PF6 –, or BF4 –). We investigate the thin-film self-assembly of block copolymers as a function of device performance. Overall, a mixed orientation at the interface leads to improved device performance, while predominantly hexagonal packing leads to nonfunctional devices, regardless of the anion present. These PIL gated OTFTs were characterized with a threshold voltage below 1 V, making understanding of their structure–property relationships crucial to enabling the further development of high-performance gating materials.

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Electrolyte-Gated Field Effect Transistors in Biological Sensing: A Survey of Electrolytes

Cited by 25 publications

References 120 publications

The Characteristics Analysis of a Microfluid-Based EGFET Biosensor with On-Chip Sensing Film for Lactic Acid Detection

The Characteristics Analysis of a Microfluid-Based EGFET Biosensor with On-Chip Sensing Film for Lactic Acid Detection

Electrolyte-gated transistors for enhanced performance bioelectronics

Poly(ionic liquid) Gating Materials for High-Performance Organic Thin-Film Transistors: The Role of Block Copolymer Self-Assembly at the Semiconductor Interface

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