An Enzyme-Free Impedimetric Sensor Based on Flower-like NiO/Carbon Microspheres for L-Glutamic Acid Assay

Area of Science:

• Electrochemistry
• Materials Science
• Biosensing

Background:

• L-glutamic acid (LGA) is a vital neurotransmitter and widely used food additive.
• Accurate detection of LGA is crucial for healthcare and food industry applications.
• Development of sensitive and selective sensors for LGA is an ongoing research area.

Purpose of the Study:

• To develop a non-enzymatic electrochemical sensor for L-glutamic acid (LGA) detection.
• To synthesize and characterize flower-like nickel oxide/carbon (fl-NiO/C) microspheres for sensor applications.
• To evaluate the sensor's performance in detecting LGA in complex matrices like blood plasma.

Main Methods:

• Flower-like nickel oxide/carbon (fl-NiO/C) microspheres were synthesized using metal-organic frameworks (MOFs) and calcination.
• Characterization of fl-NiO/C microspheres using FTIR, XRD, EDX, and FE-SEM.
• Fabrication of an impedimetric electrochemical sensor by modifying a glassy carbon electrode with fl-NiO/C and employing electrochemical impedance spectroscopy (EIS) for LGA detection.

Main Results:

• The fl-NiO/C microspheres exhibited controllable microstructures and were successfully synthesized.
• The developed impedimetric sensor showed excellent catalytic activity and selectivity for LGA detection.
• The sensor achieved a broad detection range (10–800 μM), high sensitivity (486.9 µA.mM^-1.cm^-2), and a low detection limit (1.28 µM).
• The sensor's performance in detecting LGA in blood plasma samples was comparable to High-Performance Liquid Chromatography (HPLC) methods.

Conclusions:

• The novel fl-NiO/C microspheres are effective modifiers for developing high-performance electrochemical sensors.
• The non-enzymatic impedimetric sensor demonstrates significant potential for accurate and sensitive LGA detection.
• This work paves the way for advanced biosensing applications utilizing MOF-derived materials.