Table 1 Application of nanomaterials and hydrogels in bioelectronics

Nanomaterials

Metal nanomaterials

High biocompatibility, optical polarizability, and catalytic activity

Chemical and biological sensors using surface plasmon resonance (SPR) for real-time and label-free detection of analytes

[31]

Carbon nanomaterials

Excellent flexibility, electrochemical stability, and high carrier mobility

Microelectrochemical devices, soft sensors, and actuators

[35]

Transition metal dichalcogenides (TMDs)

Wide bandgap, atomic-scale thickness, and favorable electrical properties

Applications in electronics such as semiconductors and superconductors

[38]

MXene

Distinctive mechanical strength, high electrical conductivity, and strain-tunable energy storage

Fabrication of flexible devices such as circuit breakers and electrical switches

[40]

Hydrogels

Natural

Collagen

High biocompatibility and biodegradability

Fabrication of 3D scaffolds and biological cues for cell adhesion and proliferation

[46]

Gelatin

High biocompatibility, biodegradability, non-immunogenicity, and capacity for modification at the amino acid level

Hard- and soft-tissue engineering, drug delivery, and biological glues

[47]

Matrigel

Providing multiple adhesion sites for cell attachment as well as proteins such as growth factors and transforming growth factors

Culturing of 2D cells and generation and encapsulation of 3D organoids or tissues

[48]

Biocompatible synthetic

Poly(acrylamide) (PAAm)

High water content, biocompatibility, non-biodegradability, and formation of various shapes

Solid biomedical devices such as contact lenses

[49]

Polyethylene glycol (PEG)

Superior hydrophilicity, lack of immunogenicity, high biocompatibility, and resistance to protein adsorption

Fabrication of scaffolds for tissue engineering and drug delivery

[50]

Poly(vinyl alcohol) (PVA)

Excellent hydrophilicity, biodegradability, and biocompatibility

Tissue engineering for regenerating tissues and organs including heart valves, corneal implants, and cartilage tissue substitutes

[51]

Biohybrid hydrogels

Nitro-dopamine-modified magnetic nanoparticle (MNP) with collagen-based hydrogel

Increase in the mechanical stiffness of the collagen-based hydrogel

Controlling single-cellular behavior

[67]

Ti₃C₂T_x MXene-incorporated chitosan-hyaluronate hydrogel

Control of the porosity of the chitosan-hyaluronate hydrogel

Imparting antibacterial properties to the hydrogel

[68]

Reduced graphene oxide (rGO)-incorporated PAAm hydrogel

Increase in the electrical conductivity of the PAAm hydrogel

Simultaneous delivery of electrical and mechanical cues to biological systems

[69]