An interleukin-6 ZnO/SiO(2)/Si surface acoustic wave biosensor

Area of Science:

• Materials Science
• Biotechnology
• Electrical Engineering

Background:

• Interleukin-6 (IL-6) is a key biomarker in various inflammatory and autoimmune diseases.
• Accurate and rapid detection of IL-6 is crucial for timely diagnosis and treatment monitoring.
• Existing detection methods may lack the sensitivity, speed, or portability required for widespread clinical application.

Purpose of the Study:

• To develop and characterize a novel high-sensitivity ZnO/SiO(2)/Si Love mode surface acoustic wave (SAW) biosensor for detecting interleukin-6 (IL-6).
• To evaluate the performance of the biosensor with different functionalization methods and operating frequencies.
• To assess the biosensor's capability for detecting IL-6 in complex biological samples like human serum.

Main Methods:

• Fabrication of ZnO/SiO(2)/Si Love mode SAW biosensors operating at 747.7 MHz and 1.586 GHz.
• Functionalization of the ZnO surface by immobilizing monoclonal IL-6 antibodies via direct adsorption and covalent binding.
• Morphological analysis using scanning electron microscopy (SEM).
• Quantification of immobilized IL-6 protein by measuring the frequency shift of the SAW resonator.

Main Results:

• The biosensor demonstrated high sensitivity for IL-6 detection.
• Extended linearity was observed, improving with higher sensor frequency and specific antibody immobilization.
• Preliminary measurements successfully detected low levels of IL-6 in normal human serum.
• The biosensor showed potential for integration with CMOS Si chips for portable, real-time detection systems.

Conclusions:

• The developed ZnO/SiO(2)/Si Love mode SAW biosensor is a promising platform for sensitive and specific IL-6 detection.
• The biosensor's performance is influenced by operating frequency and antibody immobilization strategy.
• The technology holds potential for integration into portable, real-time diagnostic systems for interleukin family proteins in serum.