Enhanced Cell Capture on Functionalized Graphene Oxide Nanosheets through Oxygen Clustering

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• Rising global incidence of cancer and infectious diseases necessitates advanced diagnostic and monitoring techniques.
• Efficient isolation of cells and biomolecules from whole blood is crucial for downstream analyses.
• Graphene oxide (GO) shows promise for biosensing due to its 2D structure and functionalization capabilities, but its direct use limits performance.

Purpose of the Study:

• To develop a sensitive, microfluidic-free device for efficient capture of Class-II MHC-positive cells from murine whole blood.
• To explore the impact of structural modification of graphene oxide (GO) on biosensing device performance.
• To investigate a scalable and cost-effective method for improving GO functionalization.

Main Methods:

• A mild thermal annealing treatment was applied to graphene oxide (GO) substrates, inducing a phase transformation via oxygen clustering.
• Experimental observations and molecular dynamics (MD) simulations were used to analyze the GO substrate modifications.
• A planar device was fabricated on the treated GO substrates for cell capture experiments.

Main Results:

• Thermal annealing significantly improved the reactivity and functionalization density of GO substrates.
• The treated GO devices achieved a high cell capture efficiency of 92 ± 7% at room temperature.
• This represents nearly double the efficiency (54 ± 3%) compared to devices using as-synthesized GO.

Conclusions:

• Mild thermal annealing is a scalable and cost-effective method to enhance graphene oxide (GO) functionalization for biosensing applications.
• The improved GO substrates enable highly efficient capture of specific cells from whole blood.
• This approach offers significant potential for developing next-generation diagnostic and monitoring devices.