Cross-Platform Biosensing of Immune Receptors Using Peptide-Functionalized Graphene

Area of Science:

• Biomaterials Science
• Immunology
• Nanotechnology

Background:

• Cell-surface immune receptor changes are crucial early indicators of immune responses.
• Existing biosensors primarily detect soluble disease markers, not cell-surface receptors directly.
• There is a need for sensitive, platform-independent detection of immune receptors on living cells.

Purpose of the Study:

• To develop and validate a peptide-functionalized graphene biosensor for sensitive detection of specific immune receptors on living cells.
• To demonstrate the biosensor's capability in both optical (SPR) and electrical (gFET) formats.
• To highlight the potential of this technology for diagnostics and immune monitoring.

Main Methods:

• Peptide-functionalization of graphene for specific immune receptor targeting.
• Utilized graphene-enhanced surface plasmon resonance (SPR) for optical detection.
• Employed graphene field-effect transistors (gFETs) for electrical detection.
• Validated specificity using HEK293T cells overexpressing Formyl peptide receptor 2 (FPR2).
• Demonstrated detection on primary human neutrophils.

Main Results:

• Achieved highly sensitive and reproducible detection of Formyl peptide receptor 2 (FPR2) on living cells.
• Confirmed target specificity using engineered cell lines.
• Successfully detected FPR2 on primary human neutrophils at low cell concentrations (<10,000 cells/mL).
• Demonstrated comparable performance across both SPR and gFET platforms.

Conclusions:

• Peptide-functionalized graphene biosensors offer a sensitive and reliable method for detecting immune receptors on living cells.
• The dual-platform approach (SPR and gFET) provides versatility for different diagnostic needs.
• This technology holds significant potential for point-of-care diagnostics, immune monitoring, and early sepsis triage.