Immunosensor for detection of inhibitory neurotransmitter gamma-aminobutyric acid using quartz crystal microbalance

Area of Science:

• Biosensors
• Neuroscience
• Analytical Chemistry

Background:

• Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system.
• Accurate sensing of GABA is crucial for understanding neurological functions and disorders.

Purpose of the Study:

• To develop and characterize a novel piezoelectric immunosensor for the sensitive detection of GABA.
• To investigate the real-time binding kinetics of anti-GABA antibodies to a functionalized sensor surface.

Main Methods:

• Fabrication of a piezoelectric sensor with a dextran-modified self-assembled monolayer on gold electrodes.
• Immobilization of GABA onto the dextran layer to create a biosensing interface.
• Real-time monitoring of anti-GABA antibody binding using piezoelectric crystal analysis.

Main Results:

• The immunosensor demonstrated label-free, real-time detection of anti-GABA antibody binding.
• The equilibrium association constant (K(eq)) was determined to be 14.5 µg/mL.
• The detection limit for anti-GABA was approximately 10 nM, with a sensitivity of 13.6 ng/mL x Hz.
• The sensor achieved a detection limit of approximately 42 µM for free GABA in competitive assays.

Conclusions:

• A functionalized piezoelectric immunosensor was successfully developed for GABA detection.
• The sensor provides sensitive and quantitative measurement of GABA.
• This platform holds potential for applications in neuroscience research and diagnostics.