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Article

Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors

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Food Quality and Safety Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
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2D Materials and Devices Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
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Nanomedicine Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
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Nano-ICs Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
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Center of Physics, University of Minho, 4710-057 Braga, Portugal
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Authors to whom correspondence should be addressed.
Current Address: 3B’s Research Group, I3Bs—Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, 4805-017 Guimarães, Portugal.
Biosensors 2021, 11(1), 24; https://doi.org/10.3390/bios11010024
Received: 22 December 2020 / Revised: 14 January 2021 / Accepted: 15 January 2021 / Published: 17 January 2021
(This article belongs to the Special Issue Field-Effect Transistors for Biosensing Applications)
Liquid-gated Graphene Field-Effect Transistors (GFET) are ultrasensitive bio-detection platforms carrying out the graphene’s exceptional intrinsic functionalities. Buffer and dilution factor are prevalent strategies towards the optimum performance of the GFETs. However, beyond the Debye length (λD), the role of the graphene-electrolytes’ ionic species interactions on the DNA behavior at the nanoscale interface is complicated. We studied the characteristics of the GFETs under different ionic strength, pH, and electrolyte type, e.g., phosphate buffer (PB), and phosphate buffer saline (PBS), in an automatic portable built-in system. The electrostatic gating and charge transfer phenomena were inferred from the field-effect measurements of the Dirac point position in single-layer graphene (SLG) transistors transfer curves. Results denote that λD is not the main factor governing the effective nanoscale screening environment. We observed that the longer λD was not the determining characteristic for sensitivity increment and limit of detection (LoD) as demonstrated by different types and ionic strengths of measuring buffers. In the DNA hybridization study, our findings show the role of the additional salts present in PBS, as compared to PB, in increasing graphene electron mobility, electrostatic shielding, intermolecular forces and DNA adsorption kinetics leading to an improved sensitivity. View Full-Text
Keywords: liquid gate; graphene; Debye length; phosphate buffer (PB); phosphate buffer saline (PBS); salts; DNA liquid gate; graphene; Debye length; phosphate buffer (PB); phosphate buffer saline (PBS); salts; DNA
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MDPI and ACS Style

Purwidyantri, A.; Domingues, T.; Borme, J.; Guerreiro, J.R.; Ipatov, A.; Abreu, C.M.; Martins, M.; Alpuim, P.; Prado, M. Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors. Biosensors 2021, 11, 24. https://doi.org/10.3390/bios11010024

AMA Style

Purwidyantri A, Domingues T, Borme J, Guerreiro JR, Ipatov A, Abreu CM, Martins M, Alpuim P, Prado M. Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors. Biosensors. 2021; 11(1):24. https://doi.org/10.3390/bios11010024

Chicago/Turabian Style

Purwidyantri, Agnes, Telma Domingues, Jérôme Borme, Joana R. Guerreiro, Andrey Ipatov, Catarina M. Abreu, Marco Martins, Pedro Alpuim, and Marta Prado. 2021. "Influence of the Electrolyte Salt Concentration on DNA Detection with Graphene Transistors" Biosensors 11, no. 1: 24. https://doi.org/10.3390/bios11010024

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