Bimetallic nanocolloidal plasmonic array for polyphenol characterization and calibration-free antioxidant capacity...

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Food Science

Background:

• Phenolic compounds (PC) are vital antioxidants found in various food matrices.
• Accurate and accessible methods for evaluating PC patterns and antioxidant capacity (AoC) are crucial for food quality assessment.
• Current methods can be complex and require specialized equipment.

Purpose of the Study:

• To develop an untargeted, nanoparticle-based approach for evaluating phenolic compound patterns and antioxidant capacity.
• To create a method that is simple, rapid, and potentially smartphone-operable.
• To establish a reliable alternative to conventional analytical techniques.

Main Methods:

• Utilized bimetallic silver/gold plasmonic nanoparticles as probes.
• Leveraged the ability of phenolic compounds to influence nanocolloidal probe formation and conformation.
• Developed characteristic plasmonic and colorimetric tags based on phenolic compound amount and class.
• Employed smartphone-based analysis for colorimetric response to determine antioxidant capacity score without calibration.
• Introduced plasmonic indexes for assessing dominant phenolic compound classes.

Main Results:

• The bimetallic nanostructures generated distinct plasmonic and colorimetric signals corresponding to different phenolic compounds.
• Plasmonic indexes effectively identified dominant phenolic compound classes.
• Smartphone-based colorimetric analysis provided a reliable antioxidant capacity score.
• The method demonstrated consistency with High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS/MS) and conventional photometric assays.
• Successfully classified different food samples based on their phenolic compound profiles and antioxidant capacity.

Conclusions:

• The proposed bimetallic plasmonic nanoparticle approach offers an effective untargeted method for phenolic compound pattern identification and antioxidant capacity evaluation.
• This technique provides a simple, calibration-free, and accessible tool for food analysis.
• The integration of smartphone technology enhances the practicality and potential for widespread application of this method.