Amperometric microsensor based on nanoporous gold for ascorbic acid detection in highly acidic biological extracts

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Tailoring the structure of high surface area porous metallic frameworks like Nanoporous Gold (NPG) is a key strategy for developing advanced electrochemical sensors.
• NPG's unique morphology and high surface area offer potential for enhanced electrocatalytic activity.

Purpose of the Study:

• To design a sensitive, selective, and robust electroanalytical platform based on Nanoporous Gold (NPG) for detecting ascorbic acid (AA).
• To optimize NPG film electrodeposition for improved amperometric detection of AA in biological samples.

Main Methods:

• NPG films were fabricated on gold microelectrodes via potentiostatic electrodeposition.
• Electron microscopy was used to characterize the NPG structure.
• Amperometric measurements were optimized and performed at a specific potential in acidic electrolyte.

Main Results:

• Optimized NPG films exhibited enhanced electron transfer kinetics and significantly increased oxidation peak current for AA compared to bare gold electrodes.
• The NPG-based sensor demonstrated a thousand-fold increase in sensitivity, reaching 2 nA μmol⁻¹ L⁻¹, with a detection limit of 2 μmol L⁻¹.
• The microsensor proved selective, reproducible, and stable for AA determination in acidic biological extracts.

Conclusions:

• NPG is a highly effective material for developing sensitive and selective electrochemical sensors.
• The developed NPG-based platform is suitable for quantifying ascorbic acid in complex biological matrices like fungal and plant extracts.