Fluorescence detection of cholesterol using a nitrogen-doped graphene quantum dot/chromium picolinate complex-based...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Nitrogen-doped graphene quantum dots (N-GQDs) offer excellent biocompatibility and photostability for bio-applications.
• Chromium picolinate (CrPic) is explored for its potential interaction with N-GQDs and biological molecules.
• Developing sensitive and selective cholesterol detection methods is crucial for clinical diagnostics.

Purpose of the Study:

• To develop an environmentally-friendly fluorescence sensor for cholesterol detection.
• To utilize the fluorescence enhancement properties of N-GQDs/CrPic for sensing applications.
• To investigate the mechanism of cholesterol detection based on fluorescence changes.

Main Methods:

• Synthesized N-GQDs using a facile hydrothermal approach.
• Grafted CrPic onto N-GQDs via cysteamine (Cys) linker.
• Exploited photoinduced electron transfer (PET) and fluorescence enhancement for cholesterol detection.

Main Results:

• Successfully constructed an N-GQDs/CrPic-based sensor for cholesterol detection.
• Achieved a linear detection range of 0–520 μM for cholesterol.
• Determined a low limit of detection (LOD) of 0.4 μM for cholesterol.
• Demonstrated sensor applicability in human serum with good reproducibility and precision.

Conclusions:

• The N-GQDs/CrPic sensor provides a sensitive and selective method for cholesterol determination.
• The sensing mechanism involves the impedance of electron transfer from CrPic to N-GQDs upon cholesterol binding.
• The developed sensor exhibits practical utility for cholesterol analysis in biological samples.