Graphene Amination towards Its Grafting by Antibodies for Biosensing Applications

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.

Automated summary

In this study, the feasibility of aminated graphene for covalently conjugating monoclonal antibodies to human IgG immunoglobulins was thoroughly examined. Core-level spectroscopy methods were applied to investigate the chemistry and electronic structure changes of aminated graphene before and after immobilization of monoclonal antibodies. Electron microscopy techniques were used to assess the morphology alterations of graphene layers during derivatization protocols. Chemiresistive biosensors composed of aerosol-deposited layers of aminated graphene with conjugated antibodies were fabricated and tested, demonstrating selective response to IgM immunoglobulins with a low limit of detection of 10 pg/mL. These findings advance the application of graphene derivatives in biosensing and provide insights into the morphology and physics changes of graphene upon functionalization and covalent grafting by biomolecules.