Field-effect transistor biosensors with two-dimensional black phosphorus nanosheets

Area of Science:

• Materials Science
• Nanotechnology
• Biosensing

Background:

• Field-effect transistors (FETs) are crucial for biosensing.
• Black phosphorus (BP) offers unique electronic properties for FET applications.
• Developing sensitive and selective biosensors remains a key challenge.

Purpose of the Study:

• To fabricate a black phosphorus (BP)-based field-effect transistor (FET) biosensor.
• To investigate the BP FET biosensor's sensitivity and selectivity for detecting human immunoglobulin G (h-IgG).
• To evaluate BP's potential as a sensing channel material in FET biosensors.

Main Methods:

• Fabrication of a FET biosensor using mechanically exfoliated few-layer BP nanosheets as the conducting channel.
• Surface functionalization of BP with gold nanoparticle-antibody conjugates for antigen recognition.
• Measurement of sensor response via changes in electrical resistance due to antigen-antibody binding.

Main Results:

• The BP FET biosensor demonstrated high sensitivity with a lower limit of detection (LOD) of approximately 10 ng/ml for h-IgG.
• The biosensor exhibited excellent selectivity towards human immunoglobulin G.
• Antigen adsorption induced a gate potential, altering the drain-source current, confirming sensor functionality.

Conclusions:

• The developed black phosphorus FET biosensor shows significant promise for sensitive and selective biomolecule detection.
• BP's properties make it an outstanding material for the sensing channel in FET-based biosensor applications.
• This work highlights a new avenue for advanced biosensing platforms.