Hydrogel Gate Graphene Field-Effect Transistors as Multiplexed Biosensors

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Materials Science

Background:

• Nanoscale field-effect transistors (FETs) offer sensitive, label-free biochemical signal detection.
• Translating FET sensors to practical biomedical applications faces challenges like stability and specificity.
• Bioactive hydrogels present a promising material for overcoming these limitations.

Purpose of the Study:

• To develop and validate a novel FET sensor platform utilizing bioactive hydrogels as the gate material.
• To demonstrate enhanced performance in terms of sensitivity, specificity, and stability for biosensing.
• To present a new biointegration strategy for multiplexed detection of analytes.

Main Methods:

• Spatially defined photopolymerization of polyethylene glycol on graphene FETs.
• Independent encapsulation of multiple biospecific receptors within the hydrogel gate.
• Integration and testing of penicillinase for penicillin detection and multiplexed sensing with acetylcholinesterase.

Main Results:

• Real-time, label-free detection of penicillin down to 0.2 mM was achieved via hydrogel-mediated penicillinase.
• Multiplexed functionalization demonstrated highly specific sensing capabilities.
• Hydrogel gates significantly reduced non-specific binding and preserved enzyme activity for over a week.

Conclusions:

• Bioactive hydrogels effectively address key limitations in traditional FET biosensors.
• This approach enables robust, multiplexed detection of bioanalytes on a single platform.
• The developed strategy facilitates advancements in healthcare research and diagnostics.