A Sensor to Analyze Fish Freshness: A Virtual Sensor Array Based on an Electrochemical Chemotransistor.

Area of Science:

• Electrochemistry
• Food Science
• Sensor Technology

Background:

• Accurate fish freshness assessment is crucial for food safety and quality control.
• Existing methods for determining fish spoilage lack quantitative precision and real-time capabilities.
• A quantitative definition of fish freshness is needed to estimate remaining storage time.

Purpose of the Study:

• To develop and validate an electrochemical sensor system for quantitatively measuring fish freshness.
• To establish a method for predicting the remaining storage duration of raw fish.
• To utilize a virtual array of electrochemical chemotransistor-based chemical sensors for this purpose.

Main Methods:

• Optimization of a novel electrolyte comprising a chloride-containing ionic liquid and polymeric acid mixture for sensor stability and performance.
• Application of polyaniline in various redox states as a chemosensitive material with electrically controlled affinity.
• Development of a sensor system utilizing a virtual array of electrochemical chemotransistors and a silver/silver chloride reference electrode.

Main Results:

• The sensor system demonstrated effective trimethylammonium detection.
• Complex, non-exponential, and non-monotonic sensor responses were observed for fish samples, correlating with storage duration.
• A descriptor-based approach was introduced to characterize these complex responses for freshness assessment.

Conclusions:

• The developed sensor system successfully estimates fish storage time based on a quantitative definition of freshness.
• The approach allows for the categorization of fish product quality and prediction of remaining shelf life.
• This technology offers a promising tool for objective and quantitative assessment of fish freshness.