A novel and effective surface design: conducting polymer/β-cyclodextrin host-guest system for cholesterol biosensor

Area of Science:

• Electrochemistry
• Biomaterials Science
• Analytical Chemistry

Background:

• Supramolecular chemistry and conducting polymers (CPs) offer advanced immobilization matrices for biomolecules.
• Developing efficient biosensors for biomolecule detection is crucial in diagnostics.

Purpose of the Study:

• To construct an amperometric biosensor for cholesterol detection using a novel conducting polymer (PSBTz) and β-cyclodextrin (β-CD).
• To design and synthesize an alkyl chain-containing conducting polymer for enhanced biomolecule immobilization.

Main Methods:

• Electropolymerization of PSBTz and β-CD on a graphite electrode.
• Covalent immobilization of cholesterol oxidase (ChOx) using N,N′-carbonyldiimidazole (CDI).
• Amperometric detection at -0.7 V vs Ag/AgCl in phosphate buffer (pH 7.0).
• Characterization using SEM and CV.

Main Results:

• The PSBTz/β-CD matrix provided effective immobilization and orientation of ChOx.
• Key performance metrics: KM(app) of 28.9 μM, Imax of 12.1 μA, LOD of 0.005 μM, and sensitivity of 5.77 μA/μM cm(2).
• Successful application in determining cholesterol in blood samples.

Conclusions:

• The fabricated amperometric biosensor demonstrates high sensitivity and stability for cholesterol determination.
• The novel PSBTz/β-CD matrix is a promising platform for enzyme immobilization in biosensor development.