Ultrasensitive biosensing platform for Mycobacterium tuberculosis detection based on functionalized graphene devices

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Infectious Disease Diagnostics

Background:

• Tuberculosis (TB) poses a significant global health burden, with current diagnostic methods being slow and requiring specialized facilities.
• Point-of-care (POC) detection of TB is challenging due to limitations in existing diagnostic technologies.

Purpose of the Study:

• To develop a highly sensitive graphene-based field-effect transistor (GFET) biosensor for the rapid, POC detection of Mycobacterium tuberculosis.
• To functionalize GFETs for effective antibody conjugation to detect the MPT64 protein, a biomarker for TB.

Main Methods:

• Functionalization of graphene channels with 1,5-diaminonaphthalene and glutaraldehyde linkers for antibody immobilization.
• Confirmation of linker and antibody immobilization using Raman spectroscopy and X-ray photoelectron spectroscopy.
• Real-time detection of MPT64 protein using the antibody-functionalized GFET biosensor.

Main Results:

• The GFET biosensor demonstrated highly sensitive detection of MPT64 protein with a limit of detection as low as 1 fg/mL.
• Characterization confirmed uniform immobilization of linker molecules and successful antibody conjugation on the graphene surface.
• The GFET biosensor exhibited superior sensitivity compared to traditional rapid detection tests (RDTs) and enzyme-linked immunosorbent assays (ELISAs), albeit with a smaller dynamic range.

Conclusions:

• The developed GFET biosensor platform provides a sensitive and rapid POC detection method for TB.
• This technology can overcome the limitations of existing diagnostic tools, enabling earlier TB detection or relapse management.
• The GFET biosensor holds potential for improving infectious disease diagnostics, particularly for resource-limited settings.