Development of a novel biosensor based on a conducting polymer.

Area of Science:

• Electrochemistry
• Biosensor technology
• Biomedical engineering

Background:

• Cholesterol biosensors are crucial for monitoring health and food quality.
• Existing biosensors often face limitations in sensitivity and reliability.
• Novel immobilization strategies are needed to improve biosensor performance.

Purpose of the Study:

• To develop a highly sensitive and reliable amperometric cholesterol biosensor.
• To utilize a novel electrochemically deposited polymer matrix for enzyme immobilization.
• To enhance biosensor characteristics without using membranes or covalent bonds.

Main Methods:

• Fabrication of an amperometric cholesterol biosensor using graphite electrodes.
• Electrochemical deposition of 2-(4-fluorophenyl)-4,7-di(thiophene-2-yl)-1H-benzo[d]imidazole (BIPF) as an immobilization matrix.
• Immobilization of cholesterol oxidase (ChOx) onto the BIPF matrix.
• Amperometric measurement of cholesterol at -0.7 V vs. Ag/AgCl in phosphate buffer (pH 7.0).

Main Results:

• Achieved sensitive and reliable cholesterol detection through π-π stacking and H-bond formation between BIPF and ChOx.
• Determined optimal conditions for the biosensor, yielding a K(M)app of 4.0 nM and I(max) of 2.27 µA.
• Calculated a limit of detection (LOD) of 0.404 µM and a sensitivity of 1.47 mA/mM cm(2).

Conclusions:

• A novel and accurate cholesterol biosensor was successfully developed.
• The BIPF matrix provides an effective platform for sensitive and reliable enzyme immobilization.
• The developed biosensor demonstrates potential for accurate total cholesterol determination in food samples.