Site-Specific One-to-One Click Coupling of Single Proteins to Individual Carbon Nanotubes: A Single-Molecule Approach

Abstract

We report the site-specific coupling of single proteins to individual carbon nanotubes (CNTs) in solution and with single-molecule control. Using an orthogonal Click reaction, Green Fluorescent Protein (GFP) was engineered to contain a genetically encoded azide group and then bound to CNT ends in different configurations: in close proximity or at longer distances from the GFP's functional center. Atomic force microscopy and fluorescence analysis in solution and on surfaces at the single-protein level confirmed the importance of bioengineering optimal protein attachment sites to achieve direct protein-nanotube communication and bridging.

A review of the interfacial characteristics of polymer nanocomposites containing carbon nanotubes

“…[49][50][51] Atomic force microscopy has become an important technique in the eld of composite materials due to its unique ability to image and characterize structures in liquid, ambient, and vacuum environments. [52][53][54] Recently, light, Table 1 Comparison of various mechanical techniques used for dispersing carbon nanotubes in a polymer matrix Technique neutron, and small-angle X-ray scattering techniques have also been used to quantitatively analyze the structure of carbon nanotubes in suspensions. Electron microscopy techniques are in principle more powerful than scattering techniques for elucidating the morphologies of polymer nanocomposite materials.…”

A One‐Step Chemical Strategy for the Formation of Carbon Nanotube Junctions in Aqueous Solution: Reaction of DNA‐Wrapped Carbon Nanotubes with Diazonium Salts

“…For these studies, we employed DNA‐wrapped, hence water soluble, SWCNTs, and took advantage of carboxylic terminal functionalities to tether individual molecules to nanotubes via simple amidation reactions. While this strategy allowed us to assemble in solution SWCNT‐based single‐molecule junctions, the numerous steps involved in the experimental procedure, e. g. filtrations and a two‐step functionalisation methodology, proved time consuming. Therefore, there is an interest in exploring different functionalisation schemes for the controlled fabrication of linear and branched SWCNT junctions, towards a more facile assembly.…”

Site-Specific Protein Covalent Attachment to Nanotubes and Its Electronic Impact on Single Molecule Function

“…They have particular advantages over organic molecules, not least because of their eco-friendly nature but that the protein encases the chromophore protecting it from the external environment and allowing modulation of its electronic properties through engineered changes in coupled bond networks. The protein also provides the chemical framework for facilitating light induced long range charge transfer, a critical process for fluorescence that is thought to occur by distinct pathways 36-38 . Light facilitated attachment of functional proteins to SWCTs was initially demonstrated using azF variants of the superfolder version of GFP ( Figure 1b) 30,[38][39][40][41] . The two mutants sample different configurations with respect to the b-barrel structure, distances from the functional centre (the chromophore), and different potential charge transfer pathways (vide infra).…”