Optical detection of total cholesterol based on a dye-displacement method

Area of Science:

• Biochemistry
• Analytical Chemistry
• Materials Science

Background:

• Cholesterol is a critical biomarker for cardiovascular health.
• Accurate and accessible cholesterol detection methods are essential for clinical diagnostics.
• Existing methods may involve complex procedures or toxic reagents.

Purpose of the Study:

• To develop a simple, economical, and non-toxic optical sensing probe for total cholesterol detection.
• To utilize methylene blue (MB) entrapped in agarose gel as a sensing material.
• To validate the developed method for serum sample analysis.

Main Methods:

• Methylene blue (MB) was entrapped within an agarose gel matrix.
• Cholesterol solutions were incubated with MB-entrapped agarose cubes.
• The release of MB from the gel was monitored spectrophotometrically at 664 nm.
• Calibration curves were generated by plotting MB release rate against cholesterol concentration.
• The method was characterized using FT-IR spectroscopy and cyclic voltammetry.
• The optical method was validated for total cholesterol determination in human serum samples.

Main Results:

• Cholesterol displaced methylene blue (MB) from the agarose gel, leading to its release into the solution.
• A linear response was observed for cholesterol concentrations in the range of 1 to 5 mM (40 mg/dL to 200 mg/dL).
• This concentration range covers normal and elevated human cholesterol levels.
• The optical detection method demonstrated simplicity, economy, and non-toxicity.
• Validation studies showed reasonable accuracy for total cholesterol determination in serum samples.

Conclusions:

• The MB-entrapped agarose gel serves as an effective sensing probe for optical detection of total cholesterol.
• This dye-displacement method offers a promising alternative for cholesterol quantification due to its simplicity and cost-effectiveness.
• The validated method shows potential for routine clinical use in assessing total cholesterol levels.