Biological Sensing Using Vertical MoS₂-Graphene Heterostructure-Based Field-Effect Transistor Biosensors.

Area of Science:

• Materials Science
• Nanotechnology
• Biosensor Technology

Background:

• Field-effect transistor (FET) biosensors are crucial for biomolecule detection.
• Molybdenum disulfide (MoS2) and graphene heterostructures offer unique electronic properties for enhanced sensing.
• Optimizing fabrication and functionalization is key to improving biosensor performance.

Purpose of the Study:

• To develop and investigate two MoS2-graphene heterostructure configurations (MoS2 on graphene - MG, and graphene on MoS2 - GM) for FET biosensors.
• To explore the impact of specialized functionalization techniques on biosensor performance.
• To evaluate the sensitivity and detection limits of MG and GM configurations for biomolecule sensing.

Main Methods:

• Fabrication of MG and GM heterostructures using specific functionalization agents (TESBA for MG, PBASE for GM).
• Characterization using X-ray Photoelectron Spectroscopy (XPS), Raman spectroscopy, and Atomic Force Microscopy (AFM).
• Performance evaluation through transfer curve analysis to determine sensitivity and limit of detection (LOD).

Main Results:

• Successful biofunctionalization confirmed by XPS, Raman, and AFM.
• Doping of MoS2 and graphene induced observable changes in Raman spectra and transfer curves.
• GM configurations demonstrated significantly higher sensitivity and a lower LOD compared to MG configurations.

Conclusions:

• Vertical MoS2-graphene heterostructures, particularly the GM configuration, exhibit superior sensitivity and specificity for biomolecule detection.
• The developed functionalization strategies are effective in preparing MoS2-graphene heterostructures for biosensing applications.
• GM heterostructures hold significant potential for advancing the accuracy and performance of biosensor technologies.