Liquid crystal biosensing platform based on whispering gallery mode laser for Aβ42 detection

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Biochemistry

Background:

• Alzheimer's disease (AD) is a progressive neurodegenerative disorder.
• Early diagnosis relies on biomarkers like Amyloid beta (Aβ42).
• Low blood concentrations of Aβ42 present detection challenges.

Purpose of the Study:

• To develop a rapid and real-time monitoring platform for Alzheimer's disease biomarker Aβ42.
• To create a sensitive biosensing system for low-concentration biomarker detection.
• To investigate a liquid crystal (LC) biosensing platform utilizing whispering gallery mode (WGM) lasers.

Main Methods:

• Functional modification of LC microcavities with CTAB and RNA aptamers.
• Utilizing the interaction between RNA aptamers and CTAB to induce LC molecule reorientation.
• Monitoring WGM spectral shifts caused by changes in refractive index distribution.
• Employing polarization optical microscopy and spectral analysis for dynamic monitoring.

Main Results:

• The developed LC biosensor demonstrated real-time monitoring of Aβ42.
• Quantitative monitoring showed a direct proportionality between resonance spectrum shifts and Aβ42 concentration (0-1000 pg/mL).
• Achieved a high sensitivity of 0.003 nm/pg/mL and validated practicability in mouse serum.

Conclusions:

• The WGM laser-based LC biosensing platform enables sensitive and rapid detection of Aβ42.
• The sensor is inexpensive, easy to manufacture, and fast.
• This technology holds potential for early Alzheimer's disease biomarker screening, pending further validation.