| 1. |
- Parkula, Vitaliy, et al.
(författare)
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Harnessing Selectivity and Sensitivity in Electronic Biosensing: A Novel Lab-on-Chip Multigate Organic Transistor
- 2020
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Ingår i: Analytical Chemistry. - : AMER CHEMICAL SOC. - 0003-2700 .- 1520-6882. ; 92:13, s. 9330-9337
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Tidskriftsartikel (refereegranskat)abstract
- Electrolyte gated organic transistors can operate as powerful ultrasensitive biosensors, and efforts are currently devoted to devising strategies for reducing the contribution of hardly avoidable, nonspecific interactions to their response, to ultimately harness selectivity in the detection process. We report a novel lab-on-a-chip device integrating a multigate electrolyte gated organic field-effect transistor (EGOFET) with a 6.5 mu L microfluidics set up capable to provide an assessment of both the response reproducibility, by enabling measurement in triplicate, and of the device selectivity through the presence of an internal reference electrode. As proof-of-concept, we demonstrate the efficient operation of our pentacene based EGOFET sensing platform through the quantification of tumor necrosis factor alpha with a detection limit as low as 3 pM. Sensing of inflammatory cytokines, which also include TNF alpha, is of the outmost importance for monitoring a large number of diseases. The multiplexable organic electronic lab-on-chip provides a statistically solid, reliable, and selective response on microliters sample volumes on the minutes time scale, thus matching the relevant key-performance indicators required in point-of-care diagnostics.
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| 2. |
- Sensi, Matteo, et al.
(författare)
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Modulating the Faradic Operation of All-Printed Organic Electrochemical Transistors by Facile in Situ Modification of the Gate Electrode
- 2019
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Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 4:3, s. 5374-5381
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Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors (OECTs) operated in the faradic regime were shown as outperforming transducers of bioelectric signals in vitro and in vivo. Fabrication by additive manufacturing techniques fosters OECTs as ideal candidates for point-of-care applications, as well as imposes limitations on the choice of materials and their processing conditions. Here, we address the question of how the response of fully printed OECTs depends on gate electrode material. Toward this end, we investigate the redox processes underlying the operation of OECTs under faradic regime, to show OECTs with carbon gate (C-gate) that exhibit no current modulation gate voltages <1.2 V. This is a hallmark that no interference with the faradic operation of the device enabled by redox processes occurs when operating C-gate OECTs in the low-voltage range as label-free biosensors for the detection of electroactive (bio)molecules. To tune the faradic response of the device, we electrodeposited Au on the carbon gate (Au-C-gate), obtaining a device that operates at lower gate voltage values than C-gate OECT. The presence of gold on the gate allowed further modification of the electrical performances by functionalization of the Au-C-gate with different self-assembled monolayers by fast potential-pulse-assisted method. Moreover, we show that the presence in the electrolyte solution of an external redox probe can be used to drive the faradic response of both C- and Au-C-gate OECTs, impacting on the gate potential window that yields effective drain current modulation. The results presented here suggest possible new strategies for controlling the faradic operation regime of OECTs sensors by chemical modification of the gate surface.
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| 3. |
- Sensi, Matteo, et al.
(författare)
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Monitoring DNA Hybridization with Organic Electrochemical Transistors Functionalized with Polydopamine
- 2022
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Ingår i: Macromolecular materials and engineering. - : John Wiley and Sons Inc. - 1438-7492 .- 1439-2054. ; 307:5
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Tidskriftsartikel (refereegranskat)abstract
- Organic electrochemical transistors (OECTs) are finding widespread application in biosensing, thanks to their high sensitivity, broad dynamic range, and low limit of detection. An OECT biosensor requires the immobilization of a biorecognition probe on the gate, or else on the channel, through several, often lengthy, chemical steps. In this work, a fast and straightforward way to functionalize the carbon gate of a fully screen-printed OECT by means of a polydopamine (PDA) film is presented. By chemical immobilization of an amine-terminated single-stranded oligonucleotide, containing the HSP70 promoter CCAAT sequence, on the PDA film, the detection of the complementary DNA strand is demonstrated. Furthermore, the specificity of the developed genosensor is assessed by comparing its response to the fully complementary strand with the one to partially complementary and noncomplementary oligonucleotides. The developed sensor shows a theoretical limit of detection (LOD) of 100 × 10−15 m and a dynamic range over four orders of magnitude. © 2022 The Authors.
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