scholarly journals Aptamer–field-effect transistors overcome Debye length limitations for small-molecule sensing

Science ◽  
2018 ◽  
Vol 362 (6412) ◽  
pp. 319-324 ◽  
Author(s):  
Nako Nakatsuka ◽  
Kyung-Ae Yang ◽  
John M. Abendroth ◽  
Kevin M. Cheung ◽  
Xiaobin Xu ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Debye Length ◽  
Stem Loop ◽  
Highly Sensitive ◽  
Close Proximity ◽  
Sphingosine 1 Phosphate ◽  
Specific Receptors ◽  
Highly Sensitive Detection

Detection of analytes by means of field-effect transistors bearing ligand-specific receptors is fundamentally limited by the shielding created by the electrical double layer (the “Debye length” limitation). We detected small molecules under physiological high–ionic strength conditions by modifying printed ultrathin metal-oxide field-effect transistor arrays with deoxyribonucleotide aptamers selected to bind their targets adaptively. Target-induced conformational changes of negatively charged aptamer phosphodiester backbones in close proximity to semiconductor channels gated conductance in physiological buffers, resulting in highly sensitive detection. Sensing of charged and electroneutral targets (serotonin, dopamine, glucose, and sphingosine-1-phosphate) was enabled by specifically isolated aptameric stem-loop receptors.

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

Biosensors ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Agnes Purwidyantri ◽  
Telma Domingues ◽  
Jérôme Borme ◽  
Joana Rafaela Guerreiro ◽  
Andrey Ipatov ◽  
...  
Keyword(s):  
Phosphate Buffer ◽  
Species Interactions ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Limit Of Detection ◽  
Debye Length ◽  
Intermolecular Forces ◽  
Single Layer Graphene ◽  
Dna Adsorption

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.

scholarly journals Graphene field effect transistors for highly sensitive and selective detection of K+ ions

2017 ◽  
Vol 253 ◽  
pp. 759-765 ◽  
Author(s):  
Hongmei Li ◽  
Yihao Zhu ◽  
Md. Sayful Islam ◽  
Md Anisur Rahman ◽  
Kenneth B. Walsh ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Selective Detection ◽  
Highly Sensitive

scholarly journals Targeting Antibodies to Carbon Nanotube Field Effect Transistors by Pyrene Hydrazide Modification of Heavy Chain Carbohydrates

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Steingrimur Stefansson ◽  
Hena H. Kwon ◽  
Saeyoung Nate Ahn
Keyword(s):  
Carbon Nanotube ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Polyclonal Antibodies ◽  
Debye Length ◽  
E Coli ◽  
Immobilized Antibodies ◽  
Large Size ◽  
Antibody Orientation ◽  
Effect Transistor

Many carbon nanotube field-effect transistor (CNT-FET) studies have used immobilized antibodies as the ligand binding moiety. However, antibodies are not optimal for CNT-FET detection due to their large size and charge. Their size can prevent ligands from reaching within the Debye length of the CNTs and a layer of charged antibodies on the circuits can drown out any ligand signal. In an attempt to minimize the antibody footprint on CNT-FETs, we examined whether pyrene hydrazide modification of antibody carbohydrates could reduce the concentration required to functionalize CNT circuits. The carbohydrates are almost exclusively on the antibody Fc region and this site-specific modification could mediate uniform antibody orientation on the CNTs. We compared the hydrazide modification of anti-E. coliO157:H7 polyclonal antibodies to pyrenebutanoic acid succinimidyl ester-coated CNTs and carbodiimide-mediated antibody CNT attachment. Our results show that the pyrene hydrazide modification was superior to those methods with respect to bacteria detection and less than 1 nM labeled antibody was required to functionalize the circuits.

scholarly journals Gas adsorption and light interaction mechanism in phosphorene-based field-effect transistors

2020 ◽  
Vol 22 (10) ◽  
pp. 5949-5958 ◽  
Author(s):  
Manthila Rajapakse ◽  
George Anderson ◽  
Congyan Zhang ◽  
Rajib Musa ◽  
Jackson Walter ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Field Effect ◽  
Gas Adsorption ◽  
Field Effect Transistors ◽  
Interaction Mechanism ◽  
Metal Contact ◽  
Contact Interface ◽  
Sensing Mechanism ◽  
Highly Sensitive ◽  
Barrier Model

Phosphorene-based field effect transistors are fabricated and are shown to be highly sensitive gas and photodetectors. The sensing mechanism is explained using a Schottky barrier model at the phosphorene/metal contact interface.

scholarly journals Highly Sensitive NH3 Detection Based on Organic Field-Effect Transistors with Tris(pentafluorophenyl)borane as Receptor

2012 ◽  
Vol 134 (36) ◽  
pp. 14650-14653 ◽  
Author(s):  
Weiguo Huang ◽  
Kalpana Besar ◽  
Rachel LeCover ◽  
Ana María Rule ◽  
Patrick N. Breysse ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Organic Field Effect Transistors ◽  
Highly Sensitive
Sign in / Sign up

Export Citation Format

Share Document