Amperometric bienzymatic biosensor for L-lactate analysis in wine and beer samples.

Area of Science:

• Electrochemistry
• Biosensor Technology
• Biotechnology

Background:

• L-lactate determination is crucial in food and beverage analysis.
• Existing methods may lack sensitivity or speed.
• Development of rapid and sensitive biosensors is needed.

Purpose of the Study:

• To develop a novel amperometric bienzymatic biosensor for L-lactate detection.
• To optimize the biosensor for improved sensitivity and reduced working potential.
• To validate the biosensor's performance in real-world samples like wine and beer.

Main Methods:

• Immobilization of Lactate Oxidase (LOx) and Horseradish Peroxidase (HRP) onto a carbon nanotube/polysulfone membrane using phase inversion technique on screen-printed electrodes (SPEs).
• Incorporation of ferrocene as a redox mediator to enable reduction of H(2)O(2) at -100 mV.
• Optimization of experimental conditions for enhanced sensitivity and reduced working potential.

Main Results:

• The biosensor exhibited a rapid response time of 20 seconds for L-lactate.
• High reproducibility was achieved with a relative standard deviation (RSD) of 2.7%.
• A low detection limit of 0.05 mg L(-1) and a linear range from 0.1 to 5 mg L(-1) were obtained.

Conclusions:

• The developed bienzymatic biosensor demonstrates excellent performance for L-lactate determination.
• The biosensor is suitable for analyzing L-lactic acid in wine and beer samples.
• Results showed excellent agreement with a reference spectrophotometric method, validating the biosensor approach.