Polymer–Graphene Nanocomposite Materials for Electrochemical Biosensing

Abstract

Biosensing is an important and rapidly developing field, with numerous potential applications in health care, food processing, and environmental control. Polymer-graphene nanocomposites aim to leverage the unique, attractive properties of graphene by combining them with those of a polymer matrix. Molecular imprinted polymers, in particular, offer the promise of artificial biorecognition elements. A variety of polymers, including intrinsically conducting polymers (polyaniline, polypyrrole), bio-based polymers (chitosan, polycatechols), and polycationic polymers (poly(diallyldimethylammonium chloride), polyethyleneimine), have been utilized as matrices for graphene-based nanofillers, yielding sensitive biosensors for various biomolecules, such as proteins, nucleic acids, and small molecules.

Terahertz Time-Domain Spectroscopy of Graphene Nanoflakes Embedded in Polymer Matrix

“…In order to calculate the complexσ(ω) of our graphene nanocomposite samples, we need to know the complex dependences of ε(ω) for not only the nanocomposite, but also for the neat polymer matrix. Therefore, we additionally calculated theε(ω) spectrum for each neat copolymer sample, using Equations (1)- (6), with the reference corresponding to the THz transient spectrum measured in dry nitrogen. The resulting real and imaginary parts of the graphene nanocomposite complex conductivity are plotted as symbols for both the thin (open circles) and thick (open triangles) in Figure 8.…”

“…Graphene is a two-dimensional (2-D) nanomaterial consisting of sheets of carbon atoms bonded by sp 2 bonds in a hexagonal configuration: Its unique mechanical, electrical, thermal, and optical properties have been extensively studied [2]. These properties have been leveraged in the development of a wide range of different graphene-polymer nanocomposites [3] using a variety of fabrication methods and polymer types for numerous structural and functional applications [4], including, e.g., biomedical devices [5], biosensing [6], and gas barrier membranes [7].…”

Progress in the Development of Intrinsically Conducting Polymer Composites as Biosensors

“…Graphene (GR), a 2D honeycomb lattice with an atomic thickness of sp 2 bonded carbon atom, is a monolayer of graphite that has sought considerable attention as a result of its optical, mechanical, electrical, thermal, electrochemical, and sensing properties . GR structure caters with multitudinous attributes including excellent electrical and thermal conductivity, high mechanical strength, large specific surface area, tunable band gap, high electron mobility, and room‐temperature hall effect . Principally, the structure of GR and performance benefits such as high charge mobility and surface‐to‐volume ratio can be elucidated into immensely sensitive sensing application .…”

A biofunctionalizable ink platform composed of catechol-modified chitosan and reduced graphene oxide/platinum nanocomposite

“…From the point of view of biosensing, graphene possesses a number of extremely attractive properties [3], including large specific surface area and high electron mobility. Importantly, graphene can be incorporated into polymer–graphene nanocomposites [4], gaining the additional properties of the polymer matrix, in addition to easing handling and reducing cost. Equally important have been advances in bioprinting [5], such as micro-contact printing, laser direct writing, and inkjet printing, providing cheaper, rapid alternatives to traditional lithography techniques.…”

“…The ink is formed by admixing rGO–Pt dispersions in ethylene glycol with the aqueous polymer solution and can be printed by using a commercial non-contact piezoelectric microplotter. While the application of chitosan/graphene nanocomposites for biosensing is established [4], to our knowledge, this is the first time that such a nanocomposite has been formulated as ink. Importantly, the printed nanocomposite has ample functional groups to chemically conjugate various biorecognition elements and resists the wash steps inherent in biosensing applications.…”