Optical ascorbic acid sensor based on the fluorescence quenching of silver nanoparticles

Area of Science:

• Analytical Chemistry
• Nanomaterials Science
• Biochemistry

Background:

• Ascorbic acid (AA), or Vitamin C, is a vital nutrient with significant antioxidant properties.
• Accurate quantification of AA is crucial for nutritional analysis and quality control in food and pharmaceutical products.
• Developing sensitive and selective analytical methods for AA detection remains an active area of research.

Purpose of the Study:

• To develop a novel, sensitive, and selective fluorimetric sensor for the quantitative assay of ascorbic acid (AA).
• To utilize silver nanoparticles (AgNPs) as a fluorescence quenching reagent for AA detection.
• To validate the sensor's performance and applicability in real-world samples.

Main Methods:

• Synthesis of water-soluble, stable silver nanoparticles (AgNPs) via an aqueous-gaseous phase reaction.
• Utilizing the fluorescence quenching effect of AA on AgNPs for quantitative analysis.
• Employing the Stern-Volmer law to elucidate the quenching mechanism and establish linearity.
• Optimizing reaction conditions for maximum sensitivity and selectivity.

Main Results:

• The synthesized AgNPs exhibited a narrow emission band, suitable for fluorescence probing.
• A linear relationship was observed between quenched fluorescence intensity and AA concentration (4.1 x 10(-6) to 1.0 x 10(-4) M).
• A low detection limit of 1.0 x 10(-7) M for AA was achieved.
• The sensor demonstrated excellent repeatability, with RSDs of 1.5% and 1.3% for specific AA concentrations.

Conclusions:

• The developed silver nanoparticle-based fluorimetric sensor offers a sensitive and selective method for ascorbic acid determination.
• The sensor successfully quantified ascorbic acid in practical applications, including vegetables and vitamin C tablets.
• This approach provides a valuable tool for the analysis of ascorbic acid in various matrices.