manufacturing bioelectronic devices as it is easy to modify and form various structures

with high stability. However, nucleic acid–based bioelectronic devices have some func­

tional limitations, such as low signal and electrical properties. Therefore, numerous novel

nanomaterials have been introduced to compensate for these limitations. Table 17.1 shows

representative biomaterials and their characteristics used for developing bioelectronic

devices.

17.3 Nanomaterials for Bioelectronic Devices

17.3.1 Metal Nanomaterials

Metal nanomaterials have received scientific attention for bioelectronic applications due

to their unique physical, optical, and electrical properties. The small size of the metal

nanomaterials (under 100 nm) provides excellent properties compared with bulk-scale

materials and has potential in many biological fields [16]. For example, metal NPs such as

Au, silver (Ag), and platinum (Pt) NPs have been studied due to their optical properties

called surface plasmon resonance (SPR) or localized SPR (LSPR). SPR is one of the unique

phenomena occurring at the nanoscale of noble metal NPs that emits the light combined

with the electron at the surface of the metal NPs to generate strong electron oscillations.

As shown in Figure 17.4a, Bintinger’s group developed a dual monitoring platform by

combining the SPR and electrolyte gate FET (EG-FET) [17]. For this, a 50 nm thin Au layer

was fabricated and was used for a gate electrode and the SPR active interface.

Furthermore, various types of metal nanomaterials have been studied for biosensors

based on the merits of metal nanomaterials such as the excellent catalytic properties, large

surface-to-volume ratio, and easy surface modification, which are also equally useful for

bioelectronics. Jiang’s group reported an easy fabrication strategy of porous noble metal

NPs for biosensing [18]. To fabricate the porous noble metal NPs, laser ablation toward

water (LATW) with dealloying was performed. The fabricated porous noble metal NPs

had 45 times higher local electric field intensity compared with pure noble metal NPs.

In addition, metal nanomaterials in the form of nanorods (NRs) have been hugely studied

[19]. The metal NRs have several exceptional properties such as the efficient surface

plasmon effect that depends on the aspect ratio of the NRs. Besides, numerous metal

TABLE 17.1

Representative Biomaterials and Their Characteristics Used for Developing Bioelectronic Devices

Types

Property

Type of bioelectronic

devices

Reference

Protein

• Redox properties from metal ions inside

metalloproteins

• Biological catalysts in metabolic processes

• Enzymatic reactions with certain substances

• Biomemory

• Biologic gate

• Biotransistor

[ 7– 9]

Nucleic acid • High stability

• Programmable sequences

• Various functionalities (ribozyme,

aptamer, etc.)

• Biomemory

• Biologic gate

• Biotransistor

• Bioprocessor

[ 11– 13], [ 14]

Nanomaterial-Assisted Devices

275