nanomaterials with unique compositions or structures are being reported as useful for

improving the functions of bioelectronic devices.

17.3.2 Carbon Nanomaterials

Carbon nanomaterials have several attractive properties such as the well-defined elec­

tronic property, compatibility with biological molecules, and catalytic effects [23]. Among

them, the carbon nanotube (CNT) and graphene are being largely applied to bioelectronic

devices due to their unique electrochemical properties. Graphene, a 2D hexagonal lattice

structural single layer made of sp² hybridized carbon atoms, has a large surface-to-

volume ratio and exists in a simple chemical and atomic bonding composition that is

suitable for easy surface modification and conjugating with biomaterials. Based on these,

graphene exposes a large number of carbon atoms to the environment and exhibits dif­

ferent electrical properties even with small changes to its surface or structure that are

suitable for the demonstration of bioelectronic functions. For example, Gandhi’s group

developed a graphene-based FET (GraFET) for the detection of Japanese encephalitis

virus (JEV) and avian influenza virus (AIV) [20]. The surface of the graphene was func­

tionalized with JEV and AIV antibodies by covalent bonding. Due to the large surface-to-

volume ratio, a large quantity of antibodies can absorb on the surface to achieve the

FIGURE 17.4

(a) The Au-based SPR and EG-FET gate. Adapted with permission [ 17]. Copyright (2020) American Chemical

Society. (b) A GraFET biosensor. Adapted with permission [ 20]. Copyright (2020) Springer Nature. (c) The MoS2

FET device. Adapted with permission [ 21]. Copyright (2020) Elsevier. (d) The MXene nanosheet-based bio­

sensor. Adapted with permission [ 22]. Copyright (2020) John Wiley and Sons.

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