An electrochemical microfluidic device for non-enzymatic cholesterol determination using a lab-made disposable...

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Biomedical Engineering

Background:

• Cholesterol is a vital steroid and hormone precursor.
• Blood cholesterol levels are key indicators for cardiovascular disease (CVD) risk.
• Accurate cholesterol measurement is essential for CVD management.

Purpose of the Study:

• To develop a non-enzymatic, low-cost electrochemical method for cholesterol determination in serum.
• To create a novel thread-based electroanalytical device (μTED) for facile cholesterol analysis.
• To validate the device's performance and assess its potential for clinical application.

Main Methods:

• Fabrication of a working electrode using homemade ink on a plastic substrate via a dunking process.
• Modification of the electrode with nickel ions (Ni-DWE) and integration into a microfluidic platform.
• Utilization of a thread-based electroanalytical device (μTED) with coupled electrodes for non-enzymatic cholesterol detection under alkaline conditions using Ni(II)/Ni(III) redox mediator.

Main Results:

• Optimized μTED demonstrated a linear dynamic range (LDR) from 0.25 to 25.0 μmol L⁻¹ for cholesterol.
• Achieved low limits of detection (LOD) of 0.074 μmol L⁻¹ and quantification (LOQ) of 0.24 μmol L⁻¹.
• The device showed no interference from common biological molecules (ascorbic acid, glucose, etc.) and good recovery in spiked plasma samples.

Conclusions:

• The developed non-enzymatic electrochemical method and μTED provide a sensitive and selective platform for cholesterol determination.
• The device's robustness against common interferents suggests its suitability for complex biological matrices like human plasma.
• This low-cost, facile-to-use device holds promise for accessible cardiovascular risk assessment.