Sensitive reagentless electrochemical immunosensor based on an ormosil sol-gel membrane for human chorionic...

Area of Science:

• Materials Science
• Biotechnology
• Electrochemistry

Background:

• Development of advanced materials for biosensing applications.
• Need for stable and efficient matrices for enzyme immobilization.
• Importance of sensitive detection of biomarkers like human chorionic gonadotrophin (hCG).

Purpose of the Study:

• To synthesize a novel organically modified silicate (ormosil) matrix for immunosensor preparation.
• To encapsulate horseradish peroxidase-labeled human chorionic gonadotrophin antibody (HRP-anti-hCG) within the ormosil matrix.
• To evaluate the performance of the developed immunosensor for hCG detection.

Main Methods:

• Synthesis of ormosil matrix via hydrolysis of tetraethyoxysilane and (3-aminopropyl)triethoxysilane.
• Immobilization of HRP-anti-hCG onto the ormosil matrix.
• Electrochemical characterization using differential pulse voltammetry (DPV).
• Assay development for hCG detection in human serum samples.

Main Results:

• The ormosil matrix exhibited a nanoporous structure, high electrical conductivity, mechanical stability, and hydrophilicity.
• Immobilized HRP demonstrated direct electron transfer with a rate constant of 15.8±3.8 s⁻¹.
• The immunosensor detected hCG in a linear range of 0.5–50 mIU/ml with a low limit of detection of 0.3 mIU/ml.
• The biosensor showed excellent analytical performance, reproducibility, and operational stability.

Conclusions:

• The developed ormosil-based immunosensor is effective for sensitive and stable detection of hCG.
• The ormosil matrix provides a suitable microenvironment for enzyme activity and biosensor performance.
• This technology holds promise for practical applications in clinical diagnostics.