Non-enzymatic and highly sensitive lactose detection utilizing graphene field-effect transistors

Area of Science:

• Nanomaterials Science
• Biosensor Technology
• Biochemistry

Background:

• Field-effect transistor (FET) biosensors using low-dimensional materials offer sensitive, label-free analyte detection.
• Lactose detection is vital for food safety and diagnosing conditions like lactose intolerance.

Purpose of the Study:

• To develop a highly sensitive and specific FET biosensor for lactose detection.
• To explore the potential of lectin-carbohydrate interactions for broad carbohydrate sensing.

Main Methods:

• Fabrication of a graphene FET biosensor decorated with gold nanoparticles (Au NPs).
• Functionalization of the graphene device with the carbohydrate recognition domain (CRD) of human galectin-3 (hGal-3).
• Utilizing a liquid-gate measurement configuration and exploiting lectin-glycan binding affinity.

Main Results:

• The biosensor demonstrated effective response to lactose across a dynamic range of 1 fM to 1 pM.
• Achieved a highly sensitive detection limit of 200 aM for lactose.
• Exhibited specific lactose detection at attomolar (aM) concentrations.

Conclusions:

• The developed graphene FET biosensor shows significant potential for sensitive and specific carbohydrate detection.
• This lectin-graphene FET (G-FET) sensor platform could advance disease diagnosis and food analysis.