Carbon Electrode-Based Biosensing Enabled by Biocompatible Surface Modification with DNA and Proteins

Abstract

Modification of electrodes with biomolecules is an essential first step for the development of bioelectrochemical systems, which are used in a variety of applications ranging from sensors to fuel cells. Gold is often used because of its ease of modification with thiolated biomolecules, but carbon screen-printed electrodes (SPEs) are gaining popularity due to their low cost and fabrication from abundant resources. However, their effective modification with biomolecules remains a challenge; the majority of work to-date relies on nonspecific adhesion or broad amide bond formation to chemical handles on the electrode surface. By combining facile electrochemical modification to add an aniline handle to electrodes with a specific and biocompatible oxidative coupling reaction, we can readily modify carbon electrodes with a variety of biomolecules. Importantly, both proteins and DNA maintain bioactive conformations following coupling. We have then used biomolecule-modified electrodes to generate microbial monolayers through DNA-directed immobilization. This work provides an easy, general strategy to modify inexpensive carbon electrodes, significantly expanding their potential as bioelectrochemical systems.

Emerging Design Strategies Toward Developing Next‐Generation Implantable Batteries and Supercapacitors

“…These biomolecules are anchored to material surfaces through nonspecific adsorption or coupling with surface functional groups. [ 37 ] Using graphene as an example, the inherent cytotoxicity of pristine graphene to human cells can be significantly mitigated by electrostatically adsorbing bovine serum protein and myoglobin onto its surface. Similarly, the biocompatibility of polystyrene block‐isobutylene block‐styrene can be enhanced by immobilizing extracellular matrix (ECM) on its surface.…”

One-step photo-induced modification of carbon nanotubes via polymeric diazonium chemistry

“…This strategy has opened up new avenues for not only the implementation of certain groups on the surface but also the successive fabrication of various functional materials. In particular, diazonium salts always play an important role as covalent anchors with the introduction of hydroxyl, 14,23 aniline [24][25][26] or other diverse functional groups. 15,27 This protocol would lead to significant improvements in material performance, for instance, in the wettability, 27 zeta potential 25 and corrosion inhibition efficiency.…”

“…15,27 This protocol would lead to significant improvements in material performance, for instance, in the wettability, 27 zeta potential 25 and corrosion inhibition efficiency. 28 On the other hand, pretreatments via diazonium chemistry enable the pristine inert surfaces to undergo further incorporation of polymers, [29][30][31] proteins 26,32 or ligands for certain metal ions, [33][34][35] equipping the original materials with novel properties. In general, subsequent modifications are carried out by graft-onto, 29,36 graft-from 30,31 and graftthrough 37 strategies.…”

“…38 Conversely, the graft-onto strategy serves for the incorporation of polymer precursors with uniform and precise structures. This covalent modification via esterification, 39 amidation, 26,40 click reactions 29,41 or thiol-gold interactions [42][43][44] is confined to specific functional groups or materials. Therefore, further exploration is needed for efficient grafting strategies.…”

Improving electrochemical hybridization assays with restriction enzymes

“…Electrochemical nucleic acid (NA) detection is both sensitive and portable, while maintaining a low cost for instrumentation. 8,9 Yet, most electrochemical NA detection focuses on short sequences (less than 20 bases), 10,11 making them unsuitable for ccfNA detection, as ccfNAs are generally between 40 and 500 bases. 12,13 Therefore, it is imperative to improve the NA recognition mechanism to improve the range of detectable targets.…”