Graphene Amination towards Its Grafting by Antibodies for Biosensing Applications

Abstract

The facile synthesis of biografted 2D derivatives complemented by a nuanced understanding of their properties are keystones for advancements in biosensing technologies. Herein, we thoroughly examine the feasibility of aminated graphene as a platform for the covalent conjugation of monoclonal antibodies towards human IgG immunoglobulins. Applying core-level spectroscopy methods, namely X-ray photoelectron and absorption spectroscopies, we delve into the chemistry and its effect on the electronic structure of the aminated graphene prior to and after the immobilization of monoclonal antibodies. Furthermore, the alterations in the morphology of the graphene layers upon the applied derivatization protocols are assessed by electron microscopy techniques. Chemiresistive biosensors composed of the aerosol-deposited layers of the aminated graphene with the conjugated antibodies are fabricated and tested, demonstrating a selective response towards IgM immunoglobulins with a limit of detection as low as 10 pg/mL. Taken together, these findings advance and outline graphene derivatives’ application in biosensing as well as hint at the features of the alterations of graphene morphology and physics upon its functionalization and further covalent grafting by biomolecules.

Rationalizing Graphene–ZnO Composites for Gas Sensing via Functionalization with Amines

“…Furthermore, no signs of π* resonance, corresponding to graphitic nitrogen and generally found at PEs of 400.5-400.8 eV [45,67], can be observed in the acquired N K-edge XAS spectra displayed in Figure 3a. Only prominent π* resonance of the amines centered at PEs of 401.2 eV-401.7 eV is present, accompanied by π* resonance of pyridines at a PE of 398.3 eV [22,68].…”

“…In turn, a redistribution in the integral intensities of the spectral components centered at BEs of 400.1 eV and 401.5 eV was indicated: the contribution from the former dropped from 71.83% to 52.27%, while for the latter it rose from 9.62% to 30.16%. The first of these spectral features is known to stem from the presence of primary and secondary amines [22,23], whereas the origin of the second one is more ambiguous. Commonly, it is attributed to the presence of graphitic nitrogen embedded into the graphene network [67].…”

“…In turn, aminated graphene (AmG) can be regarded as a material of choice for this purpose. AmG is presented by a pristine graphene layer, in which local areas are covalently functionalized by primary amines (-NH 2 ) at concentrations of 3-10 at.% [22][23][24], with negligible contents of other organic groups. This distinguishes AmG from graphene oxide layers covered with aminecontaining oligomers [25,26], which are often misidentified as aminated graphenes as well.…”

二维原子-分子异质结的制备及其类脑器件应用

“…; 叔丁基咔唑(t-boc)的肼 衍生物能够促使GO表面的环氧基团开环 [141] [143,144] ; 而采 用胺化还原剂可以在GO上引入氨基, 这一策略进一步 拓宽了间接修饰的可能性 [145] .…”

Filled Carbon Nanotubes: Promising Material for Applications

“…In a research paper [20], the authors studied in detail the applications of aminated graphene for the covalent conjugation of monoclonal antibodies. They applied X-ray photoelectron and absorption spectroscopies and electron microscopy to their investigations (Figure 1).…”