Label Free Detection of L-Glutamate Using Microfluidic Based Thermal Biosensor

Area of Science:

• Biosensors
• Thermoelectric devices
• Biochemical analysis

Background:

• L-glutamate is a key neurotransmitter.
• Accurate detection of L-glutamate is crucial for neurological research.
• Existing detection methods can be complex or require extensive sample preparation.

Purpose of the Study:

• To develop a sensitive thermoelectric biosensor for L-glutamate detection.
• To integrate the sensor into a micro-calorimeter for heat measurement.
• To optimize the device for efficient and low-volume sample analysis.

Main Methods:

• A micro-calorimeter with a single flow channel was fabricated.
• An antimony-bismuth (Sb-Bi) thermopile was used to measure temperature changes.
• Glutamate oxidase (GLOD) was immobilized using layer-by-layer assembly.
• Impulse injection mode minimized sample volume to 5 µL.

Main Results:

• The sensor demonstrated a sensitivity of 17.9 nVs·mM⁻¹ in the linear range of 0-54 mM (R²=0.9873).
• The lowest detection limit for L-glutamate was 5.3 mM.
• Device geometry and hydrodynamic focusing reduced the need for extensive temperature control.

Conclusions:

• The developed thermoelectric biosensor is effective for L-glutamate detection.
• The device offers high sensitivity and a low detection limit.
• This technology shows promise for efficient biochemical analysis.