Addressing the Theoretical and Experimental Aspects of Low-Dimensional-Materials-Based FET Immunosensors: A Review

Abstract

Electrochemical immunosensors (EI) have been widely investigated in the last several years. Among them, immunosensors based on low-dimensional materials (LDM) stand out, as they could provide a substantial gain in fabricating point-of-care devices, paving the way for fast, precise, and sensitive diagnosis of numerous severe illnesses. The high surface area available in LDMs makes it possible to immobilize a high density of bioreceptors, improving the sensitivity in biorecognition events between antibodies and antigens. If on the one hand, many works present promising results in using LDMs as a sensing material in EIs, on the other hand, very few of them discuss the fundamental interactions involved at the interfaces. Understanding the fundamental Chemistry and Physics of the interactions between the surface of LDMs and the bioreceptors, and how the operating conditions and biorecognition events affect those interactions, is vital when proposing new devices. Here, we present a review of recent works on EIs, focusing on devices that use LDMs (1D and 2D) as the sensing substrate. To do so, we highlight both experimental and theoretical aspects, bringing to light the fundamental aspects of the main interactions occurring at the interfaces and the operating mechanisms in which the detections are based.

Graphene electrochemical transistors decorated by Ag nanoparticles exhibiting high sensitivity for the detection of paraquat over a wide concentration range

“…Just like in this work, the Dirac point of the pristine graphene is at 0.75 V, but aer modication with Ag NPs, the Dirac point has moved to 1.02 V. It indicates that the graphene has been p-type doped due to the defects and oxygen functional groups introduced during the deposition of Ag NPs. 24,45 In fact, the position of the graphene Dirac point is also closely related to the chemical environment in which the graphene is located. 46 Because of the single-atom layer structure of graphene, every carbon atom is exposed, and it is very susceptible to the inuence of surrounding molecules, leading to the deviation or transfer of electrons, resulting in similar consequences to doping.…”

A multiscale approach for electronic transport simulation of carbon nanostructures in aqueous solvent

“…Since graphene was discovered, 1 there have been proposals for utilizing it in many different applications due to its unique properties. [2][3][4][5][6] Specifically, high surface area and good electric conductivity make graphene an excellent candidate for the active material in sensors, [7][8][9][10][11] not least for compounds of interest in biology. [12][13][14][15][16] An all-electronic graphene-based sensor operates on the assumption that the chemisorption or physisorption of external agents results in measurable changes of the electronic structure of graphene.…”

“…Since graphene was discovered, 1 there have been proposals for utilizing it in many different applications due to its unique properties. 2–6 Specifically, high surface area and good electric conductivity make graphene an excellent candidate for the active material in sensors, 7–11 not least for compounds of interest in biology. 12–16…”