Poly(p-phenyleneethynylene)-based tongues discriminate fruit juices

Area of Science:

• Analytical Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Development of sensitive and selective sensors for complex liquid analysis is crucial.
• Fluorescent conjugated polymers offer unique optical properties for sensing applications.
• Optoelectronic tongues provide a platform for multi-analyte discrimination based on chemometric analysis.

Purpose of the Study:

• To develop and evaluate a simple optoelectronic tongue for identifying and discriminating fruit juices.
• To assess the performance of a positively charged fluorescent polymer (P2) in juice analysis.
• To compare the efficacy of P2 with a negatively charged fluorescent polymer (P1).

Main Methods:

• Utilized a positively charged fluorescent polymer (P2) in an optoelectronic tongue setup.
• Tested the sensor's response to fruit juices at different pH values (3, 7, 13).
• Employed fluorescence quenching measurements and processed data using linear discriminant analysis.

Main Results:

• The optoelectronic tongue successfully identified and discriminated 14 apple, 6 grape, and 5 black currant juices.
• The positively charged polymer (P2) demonstrated high sensitivity, requiring lower analyte concentrations than the negatively charged polymer (P1).
• The system accurately classified mixtures, identifying them based on the predominant juice type (e.g., >70% red grape juice).

Conclusions:

• A simple, positively charged fluorescent polymer-based optoelectronic tongue is effective for fruit juice analysis.
• This sensing system offers high specificity and sensitivity for discriminating complex beverages.
• The developed technology holds potential for food quality control and authentication applications.