Aptasensor for amplified IgE sensing based on fluorescence quenching by graphene oxide

Area of Science:

• Nanomaterials Science
• Biotechnology
• Analytical Chemistry

Background:

• Graphene oxide (GO) possesses a unique 2D layered nanostructure and water solubility.
• Fluorescence resonance energy transfer (FRET) is a distance-dependent process used for molecular sensing.
• Immunoglobulin E (IgE) is a key biomarker in allergic diseases.

Purpose of the Study:

• To develop a highly sensitive and selective aptasensor for Immunoglobulin E (IgE) detection.
• To utilize graphene oxide (GO) as a quencher in a FRET-based sensing platform.
• To establish a quantitative method for IgE determination in biological samples.

Main Methods:

• Synthesis of water-soluble graphene oxide (GO).
• Construction of a FRET aptasensor using FITC-labeled aptamer and GO.
• Utilizing π→π stacking for aptamer adsorption onto GO.
• Measuring fluorescence recovery upon IgE binding for quantification.

Main Results:

• The aptasensor demonstrated high sensitivity for IgE detection with a linear range of 60-225 pM and a detection limit of 22 pM.
• Fluorescence quenching occurred via FRET from FITC to GO, with fluorescence recovery in the presence of IgE.
• The assay exhibited high selectivity, unaffected by other proteins like IgG, HSA, and BSA.
• Successful determination of IgE in human serum samples was achieved.

Conclusions:

• The developed GO-based FRET aptasensor provides a sensitive, selective, and efficient platform for IgE detection.
• This method offers a promising tool for clinical diagnostics and monitoring of IgE-related conditions.
• The π→π stacking interaction facilitates stable aptamer immobilization, enhancing sensor performance.