Nanostructured NiO-based reagentless biosensor for total cholesterol and low density lipoprotein detection

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Biomedical Engineering

Background:

• Cholesterol detection is crucial for cardiovascular health.
• Existing biosensors often require toxic mediators, limiting their practical application.
• Development of reagentless biosensors is a key goal in diagnostics.

Purpose of the Study:

• To develop a reagentless biosensor for detecting free cholesterol, total cholesterol, and low-density lipoprotein (LDL).
• To utilize nanostructured nickel oxide (NiO) thin film as a matrix for enhanced electrochemical performance.
• To eliminate the need for toxic mediators in cholesterol detection.

Main Methods:

• Characterization of NiO thin film using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR).
• Electrochemical analysis employing cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV).
• Development of a reagentless biosensing mechanism exploiting the redox properties of NiO.

Main Results:

• High sensitivity for free cholesterol (27 μA/mM/cm²) and total cholesterol (63 μA/mM/cm²) over wide linear ranges.
• Sensitive detection of LDL (0.12 mA/μM/cm²) within the 0.018-0.5 μM range.
• Demonstrated enhanced electron transfer and elimination of toxic mediators.

Conclusions:

• The nanostructured NiO thin film serves as an effective matrix for reagentless cholesterol and LDL biosensing.
• The developed biosensor shows high sensitivity and selectivity, promising for clinical diagnostics.
• This approach paves the way for integrated biosensors for comprehensive serum cholesterol analysis.