High-performance electrochemical biosensor for the detection of total cholesterol

Area of Science:

• Electrochemistry
• Biosensors
• Materials Science

Background:

• Cholesterol determination is crucial for clinical diagnostics and food quality control.
• Existing methods for cholesterol detection can be complex or lack sensitivity.
• Development of sensitive and selective biosensors is an active area of research.

Purpose of the Study:

• To develop a highly sensitive electrochemical biosensor for total cholesterol determination.
• To fabricate a novel biosensor using co-immobilized enzymes on a nanoporous gold substrate.
• To evaluate the biosensor's performance for clinical and food sample analysis.

Main Methods:

• Fabrication of a biosensor (Ti/NPAu/ChO(x)-HRP-ChE) by co-immobilizing cholesterol oxidase (ChO(x)), cholesterol esterase (ChE), and horseradish peroxidase (HRP) on nanoporous gold networks on a titanium substrate.
• Characterization of the nanoporous gold using SEM, EDS, and XRD.
• Electrochemical performance evaluation using cyclic voltammetry (CV).

Main Results:

• The biosensor demonstrated high sensitivity (29.33 μA mM⁻¹ cm⁻²) and selectivity.
• A low apparent Michaelis-Menten constant (K(M)(app) = 0.64 mM) indicated efficient enzyme immobilization.
• A wide linear range up to 300 mg dL⁻¹ at physiological pH (7.4) was achieved.
• Successful testing with real food samples (margarine, butter, fish oil).

Conclusions:

• The developed electrochemical biosensor offers a sensitive and selective method for total cholesterol determination.
• The biosensor's performance in physiological conditions and with real samples highlights its potential for clinical and food quality control applications.
• The use of nanoporous gold networks provides an effective platform for enzyme immobilization and enhanced biosensing performance.