Simultaneous determination of biomarkers for Alzheimer's disease using sol-gel-derived optical array biosensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Alzheimer's disease (AD) diagnosis relies on identifying key biomarkers.
• Simultaneous detection of multiple AD markers remains a challenge for current diagnostic tools.
• Optical biosensors offer high sensitivity and specificity for biomarker detection.

Purpose of the Study:

• To develop a sol-gel-derived optical array biosensor for simultaneous detection of Alzheimer's disease biomarkers.
• To evaluate the sensor's performance in detecting beta-amyloid, acetylcholine, and glutamate.
• To assess the biosensor's applicability in complex biological matrices like human serum.

Main Methods:

• Fabrication of a sol-gel-derived optical array biosensor.
• Co-immobilization of enzymes (glutamate dehydrogenase, acetylcholinesterase, horseradish peroxidase) and fluorescent dyes (carboxy SNARF-1-dextran, Amplex red, FITC-dextran).
• Simultaneous detection of beta-amyloid, acetylcholine, glutamate, and hydrogen peroxide (H2O2).

Main Results:

• The biosensor demonstrated simultaneous multianalyte detection with minimal cross-interference.
• Achieved low detection limits: H2O2 (1.57 nM), beta-amyloid (0.63 nM), glutamate (0.55 µM), and acetylcholine (1.0 µM).
• Showcased a wide dynamic range (4 orders of magnitude for beta-amyloid) and good performance in spiked human serum samples.

Conclusions:

• The developed sol-gel optical array biosensor enables simultaneous analysis of key Alzheimer's disease biomarkers.
• This technology presents a viable platform for sensitive and specific detection of multiple analytes relevant to AD.
• The biosensor shows potential for clinical diagnostics and disease monitoring.