A Sensitive Electrochemical Ascorbic Acid Sensor Using Glassy Carbon Electrode Modified by Molybdenite with...

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Development of sensitive and selective electrochemical sensors is crucial for accurate analyte determination.
• Natural molybdenite (MLN) offers potential as a cost-effective electrode material.
• Methylene blue (MB) is a redox-active molecule that can enhance sensor performance.

Purpose of the Study:

• To fabricate and characterize a non-enzymatic amperometric sensor for ascorbic acid (AA) determination.
• To investigate the analytical performance of a sensor based on natural molybdenite modified with electrodeposited methylene blue.
• To evaluate the stability, reproducibility, sensitivity, and selectivity of the developed sensor.

Main Methods:

• Fabrication of a sensor by electrodepositing methylene blue (MB) onto natural molybdenite (MLN).
• Surface morphology characterization using Advanced Mineral Identification and Characterization System (AMICS) and laser confocal high-temperature scanning microscope (LCSM).
• Electrochemical performance evaluation for ascorbic acid detection, including linear range, detection limit, response time, stability, and anti-interference capabilities.

Main Results:

• The poly(MB)/MLN sensor exhibited excellent stability, reproducibility (2.6%), sensitivity, and selectivity.
• A linear performance range from 3 to 1000 μM with a low detection limit of 0.083 μM (S/N=3) was achieved.
• The sensor demonstrated a short response time (<5 s) and maintained performance for over 20 days with good anti-interference properties.

Conclusions:

• Natural molybdenite is a viable material for fabricating efficient non-enzymatic electrochemical sensors.
• The poly(MB) modification enhances electron-transfer rates and sensor lifetime.
• The developed sensor shows significant potential for the accurate and reliable determination of ascorbic acid.