A biofunctionalized quantum dot-nickel oxide nanorod based smart platform for lipid detection.

Area of Science:

• Nanomaterials Science
• Biomedical Engineering
• Analytical Chemistry

Background:

• Low-density lipoprotein (LDL) levels are critical indicators of cardiovascular health.
• Accurate and sensitive detection of LDL in human serum is essential for early diagnosis and management of hyperlipidemia.
• Existing detection methods may require complex procedures or expensive reagents, necessitating simpler and more cost-effective alternatives.

Purpose of the Study:

• To fabricate a reagent-free, low-cost, and highly sensitive immunosensor for LDL detection.
• To utilize anti-apolipoprotein B (AAB) conjugated l-cysteine capped cadmium sulfide quantum dots (CysCdS QDs) with nickel oxide nanorods (nNiO).
• To evaluate the performance of the developed immunosensor for quantifying LDL in human serum samples.

Main Methods:

• Synthesis and characterization of nickel oxide nanorods (nNiO) and anti-apolipoprotein B (AAB) conjugated l-cysteine capped cadmium sulfide quantum dots (CysCdS QDs).
• Fabrication of the CysCdS-NiO based immunosensor platform.
• Electrochemical detection of low-density lipoprotein (LDL) using the developed immunosensor.
• Structural and morphological analysis using electron microscopy, X-ray diffraction, FTIR, and UV-visible spectroscopy.

Main Results:

• The CysCdS-NiO immunosensor demonstrated significantly improved sensitivity (32.08 μA (mg dl^-1)^-1 cm^-2) compared to nNiO alone (1.42 μA (mg dl^-1)^-1 cm^-2).
• The sensor effectively detected LDL over a wide concentration range (5-120 mg dl^-1).
• Kinetic analysis revealed a high association constant (K_a = 3.24 kM^-1 s^-1), indicating strong affinity for LDL molecules.

Conclusions:

• The developed mediator-free CysCdS-NiO immunosensor provides a sensitive and efficient platform for LDL detection.
• The excellent electron transport properties of the CysCdS-NiO nanocomposite facilitate routine quantification of LDL in real samples.
• This immunosensor represents a promising tool for low-cost, reagent-free cardiovascular risk assessment.