Highly sensitive, scalable, and rapid SARS-CoV-2 biosensor based on In₂O₃ nanoribbon transistors and phosphatase

Area of Science:

• Nanotechnology
• Biosensors
• Medical Diagnostics

Background:

• Accurate and rapid detection of SARS-CoV-2 is critical for pandemic control.
• Existing biosensors face challenges with stability and detection in various media.

Purpose of the Study:

• To develop an improved indium oxide nanoribbon field-effect transistor (FET) biosensor.
• To detect both SARS-CoV-2 antigen and antibodies with high sensitivity and stability.

Main Methods:

• Fabrication of In2O3 nanoribbon FETs using a lithography-free process.
• Utilizing a stable phosphatase enzyme reporter for signal generation.
• Detection of SARS-CoV-2 spike protein and IgG antibodies in different mediums.

Main Results:

• Achieved a limit of detection of 100 fg/mL for SARS-CoV-2 antigen.
• Achieved a limit of detection of 1 pg/mL for SARS-CoV-2 IgG antibodies in whole blood.
• Demonstrated stable performance in phosphate-buffered saline, transport medium, and whole blood.

Conclusions:

• The In2O3 FET biosensor platform offers a scalable, cost-efficient, and highly sensitive method for detecting SARS-CoV-2 biomarkers.
• The improved enzyme reporter enhances stability and shelf-life, paving the way for clinical diagnostic applications.