Magnetic Graphene Field-Effect Transistor Biosensor for Single-Strand DNA Detection

Abstract

Herein, a magnetic graphene field-effect transistor biosensor was prepared through the transfer of a chemical vapor deposition graphene film onto a glass substrate to produce a sensing film and conductive channel. By fixing 1-pyrenebutanoic acid succinimidyl ester onto graphene film as an anchor, a probe aptamer was immobilized on the graphene film in order to capture magnetically labeled complementary single-stranded DNA. Our experiments showed that, within a periodic magnetic field, the biosensor impedance exhibited a periodic oscillation, the amplitude of which was correlated to the complementary DNA concentration. Based on this principle, the magnetic graphene field-effect transistor was utilized to detect single-stranded DNA with detection limition of 1 pM. The results were rationalized using a model wherein the magnetic force causes the DNA strand to bend, thereby resulting in magnetic nanobeads/DNA modulation of the double conductive layer of graphene transistors. Furthermore, since a periodic magnetic field could be introduced to produce a periodic impedance changes of MGFETs, sampling integration could be used to improve the signal-to-noise ratio efficiently by increasing the number of periods of the external magnetic field. Therefore, a novel biosensor for DNA detection with high sensitivity has been presented in this work. Based on the detection principle, this system may also be a potential tool for detecting other bio-molecules, cells, etc.

Two-Dimensional Field-Effect Transistor Sensors: The Road toward Commercialization

“…Copyright 2020 The Royal Society of Chemistry. (d) Adapted with permission from ref , which is an open access article distributed under a Creative Commons Attribution 4.0 International License.…”

“…(1) Miniaturization . There is an ever-lasting demand to integrate more devices and functional components into modern electric systems. , By miniaturizing down to the micro- or nanoscale, a 2D FET sensor system can reduce costs, weight, and power consumption while improving detection performance at the same time. ,, However, there are many challenges in the miniaturization process, which includes a doping process, mobility engineering, and scaling effects. , Here, we list four challenges in miniaturizing 2D FET sensors: (i) Most 2D FET biochemical sensors require a reference electrode to apply a liquid-gate voltage, and this liquid-gate configuration restricts the miniaturization. , (ii) The other problem of miniaturized sensing components is the low-frequency noise. After scaling down to the nanoscale, increasing interfacial traps in 2D semiconductors cause carrier mobility fluctuation, carrier density fluctuation, or both. ,, Such fluctuations that obey the inverse frequency power law are called low-frequency noise.…”

Electrochemical Determination of 4-Bromophenoxyacetic Acid Based on CeO2/eGr Composite

“…Among these methods, electrochemical exfoliation of graphite has the advantages of being low-cost and environmentally friendly, easily made and scalable, and the electrochemical conditions are controllable. Moreover, the exfoliated graphene is a zero-gap semiconductor; it can be doped with p-block elements (N, S, P, B, and metal oxides) and d- block elements (inherent impurities) [ 26 , 28 ] to improve the HEF to promote the interaction between target molecules and the electrode. In the study of Liu [ 29 ], gold-palladium nanoparticles were cast on the graphene nano-platelets, and the nanocomposites showed high electrocatalytic ability towards the oxidation of hydrazine.…”

Edge-Enhanced Microwell Immunoassay for Highly Sensitive Protein Detection

“…Highly sensitive biosensors that can detect low concentrations of protein biomarkers and proteins secreted from single cells at an early stage of diseases are of great importance for diagnosis and therapy assessment. − The biological signals generated in antibody–antigen binding and nucleic acid hybridization are usually too weak to be detected and are thus amplified by either physical means (electronic and mechanical), , chemical means (polymerization and electrochemical), , or biological means (enzymatic reaction and fluorescence immunoassay). − The sensing platforms can be nanomaterials (such as nanoparticles and nanowires), − field-effect transistors, − microcantilevers, quartz-crystal microbalances, − optical sensors, − and electrochemical sensors . The most sensitive amperometry sensor for protein detection was reported, the detection limit of which is at sub-zeptomole levels .…”