Chitosan-functionalized Ag-Cu-ferrite nanocomposite as a high-performance electrochemical sensor for ascorbic acid...

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Analytical Chemistry

Background:

• Ascorbic acid (vitamin C) is a vital nutrient with numerous health benefits.
• Accurate and sensitive detection of ascorbic acid is crucial for nutritional monitoring and clinical diagnostics.
• Existing detection methods may lack efficiency, selectivity, or practicality for real-world applications.

Purpose of the Study:

• To develop a novel electrochemical sensor for the sensitive and selective detection of ascorbic acid.
• To functionalize silver-copper-ferrite nanoparticles with chitosan to enhance sensor performance.
• To characterize the nanocomposite material and evaluate its electrochemical properties for ascorbic acid measurement.

Main Methods:

• Synthesis and characterization of chitosan-functionalized Ag-Cu-ferrite nanoparticles (Ag_0.02Cu_0.98Fe₂O₄@chitosan).
• Fabrication of a carbon paste electrode (CPE) modified with the nanocomposite.
• Electrochemical measurements using cyclic voltammetry (CV) and chronoamperometry.
• Analysis of electrochemical response, sensitivity, selectivity, reproducibility, and repeatability.
• Computational studies including DFT, MESP, Fukui function analysis, and Monte Carlo simulations.

Main Results:

• The Ag_0.02Cu_0.98Fe₂O₄@chitosan-CPE exhibited superior electrocatalytic activity for ascorbic acid detection compared to a bare CPE.
• The sensor demonstrated a linear response with diffusion-controlled kinetics over two concentration ranges (100-300 µM and 300 µM-13 mM).
• High sensitivity (411.59 µA mM^-1 cm²), low limit of detection (89 µM), excellent selectivity, reproducibility (RSD = 1.96%), and repeatability (RSD = 1.15%) were achieved.
• The sensor showed high recovery rates (up to 98%) in real samples.
• Computational studies validated the material's reactivity and the strong affinity of ascorbic acid to the sensor surface.

Conclusions:

• The developed Ag_0.02Cu_0.98Fe₂O₄@chitosan nanocomposite sensor offers an efficient and reliable platform for ascorbic acid detection.
• Chitosan functionalization significantly enhances the electrocatalytic performance and stability of the sensor.
• The sensor's excellent analytical performance and validation through computational methods make it suitable for practical applications in vitamin C analysis.