Aptamer-based piezoelectric quartz crystal microbalance biosensor array for the quantification of IgE

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunology

Background:

• Accurate and rapid measurement of Immunoglobulin E (IgE) is crucial for diagnosing allergic diseases.
• Existing methods for IgE detection can be time-consuming and require complex sample preparation.

Purpose of the Study:

• To develop a direct aptamer-based biosensor utilizing quartz crystal microbalance (QCM) for rapid IgE quantification in human serum.
• To evaluate the specificity, sensitivity, and reusability of the developed aptamer QCM biosensor.

Main Methods:

• Immobilization of IgE-specific aptamers on a gold-coated quartz crystal surface via an avidin monolayer.
• Measurement of frequency shifts (FS) in the QCM in response to varying IgE concentrations.
• Validation of the biosensor's performance against chemiluminescence in clinical human serum samples.

Main Results:

• The aptamer QCM biosensor detected IgE with high specificity and sensitivity within 15 minutes.
• A linear correlation was observed between FS and IgE concentrations (2.5–200 µg/L) in both buffer and human serum.
• The biosensor demonstrated excellent reusability and stability over time, retaining >90% sensitivity after 3 weeks of storage.

Conclusions:

• The developed aptamer QCM biosensor provides a rapid, sensitive, and specific method for IgE measurement.
• Advantages include reusability, a low detection limit, minimal sample pretreatment, and low sample volume requirements.
• This innovative biosensor shows significant potential for sensitive protein detection in proteomics and clinical diagnostics.