In₂O₃ Nanoribbon-Based Field-Effect Transistor Biosensors for Ultrasensitive Detection of Exosomal Circulating...

Area of Science:

• Nanomaterials science
• Biosensor technology
• Molecular diagnostics

Background:

• MicroRNA (miRNA) detection is vital for early disease diagnosis, but current methods struggle with sensitivity at low concentrations.
• Field-effect transistor (FET) biosensors show promise for miRNA detection, yet ultralow concentration detection remains a challenge due to weak signals from small, low-charge molecules.

Purpose of the Study:

• To develop a highly sensitive and selective FET biosensor for attomolar miRNA detection.
• To introduce a simplified, one-step surface functionalization strategy for metal-oxide-based FETs.
• To demonstrate a label-free detection method for enhanced miRNA sensing.

Main Methods:

• Utilized an indium oxide (In2O3) nanoribbon-based FET biosensor platform.
• Developed a simplified one-step surface chemistry using a 10-(maleimidyl)decylphosphonic acid (MalC10PA) linker.
• Implemented a label-free sensing technique involving a peptide nucleic acid (PNA) probe/target RNA/DNA-biotin sandwich structure, followed by streptavidin and biotin-urease amplification.

Main Results:

• Achieved an ultralow detection limit of 0.72 attomolar (aM) for miRNAs.
• Demonstrated high selectivity against miRNAs with mismatches.
• Showcased consistent miRNA detection in patient plasma samples compared to buffer solutions.

Conclusions:

• The In2O3-nanoribbon FET biosensor platform enables highly sensitive and selective miRNA detection at attomolar levels.
• The simplified surface chemistry and urease-induced pH amplification strategy significantly enhance biosensor performance.
• This technology holds great potential for early cancer detection and highly multiplexed diagnostic applications.