Highly sensitive and accurate detection of cholesterol based on a single red upconversion biosensor

Area of Science:

• Biochemistry
• Nanotechnology
• Analytical Chemistry

Background:

• Cholesterol (CHOL) is a critical clinical indicator for cell membrane function and disease diagnosis.
• Accurate CHOL monitoring is essential for early disease prevention and management.
• Upconversion nanoparticles (UCNPs) offer advantages in biological sensing due to their deep tissue penetration and high sensitivity.

Purpose of the Study:

• To develop a dual-readout colorimetric and fluorescent sensor for accurate cholesterol detection.
• To utilize red UCNPs and TMB for a sensitive and reliable CHOL sensing system.
• To validate the sensor's performance in biological samples for clinical applications.

Main Methods:

• A dual-readout sensor was designed using single red UCNPs as fluorescent donors and TMB as a quenching agent.
• The detection mechanism and optimal experimental conditions (Fe2+ concentration, TMB concentration, reaction time) were investigated.
• The sensor's performance was evaluated using colorimetric and fluorescence detection modes.

Main Results:

• The developed sensor achieved low limits of detection for CHOL: 0.85 μM (colorimetric) and 0.63 μM (fluorescence).
• The sensor demonstrated high accuracy and reliability when measuring CHOL in serum samples, with spiked recoveries ranging from 97.1% to 103.7%.
• Both colorimetric and fluorescence modes provided comparable CHOL measurement values.

Conclusions:

• A sensitive and accurate dual-readout sensor for cholesterol detection has been successfully developed.
• The UCNP-TMB based sensing system shows significant potential for clinical diagnosis and health management.
• This approach offers a promising tool for precise cholesterol level monitoring in biological samples.