A new interference-free lysine biosensor using a non-conducting polymer film

Area of Science:

• Electrochemistry
• Biosensor Technology
• Food Science

Background:

• Accurate and rapid evaluation of food quality is crucial for consumer safety and product integrity.
• Existing methods for amino acid determination can be time-consuming and require specialized equipment.
• Electrochemical biosensors offer a promising alternative for on-site, real-time food analysis.

Purpose of the Study:

• To develop and characterize an electrochemical biosensor for the quantitative determination of lysine.
• To assess the biosensor's performance in terms of sensitivity, selectivity, and detection limits.
• To evaluate the potential application of the developed biosensor for rapid food quality assessment.

Main Methods:

• Platinum electrodes were modified via electropolymerization with 1,2-diaminobenzene (1,2-DAB) using cyclic voltammetry.
• The enzyme L-lysine-alpha-oxidase was immobilized onto the polymer-modified electrode surface via passive adsorption.
• Electrochemical measurements were performed to construct a calibration curve for lysine detection.

Main Results:

• The developed biosensor demonstrated significant reduction in the oxidation of common interferents: 100% for ascorbic acid, 99% for acetaminophen, and 99% for cysteine.
• A linear calibration curve for lysine was obtained in the concentration range of 1 x 10(-5) mol/L to 1 x 10(-3) mol/L.
• The limit of detection for lysine was determined to be 2 x 10(-7) mol/L, indicating high sensitivity.

Conclusions:

• The developed electrochemical biosensor based on 1,2-DAB modified platinum electrodes and L-lysine-alpha-oxidase is highly effective for lysine determination.
• The biosensor exhibits excellent selectivity and sensitivity, with minimal interference from common food components.
• This technology holds significant potential for rapid, reliable, and cost-effective evaluation of food quality.