Silver nanoflower-reduced graphene oxide composite based micro-disk electrode for insulin detection in serum

Area of Science:

• Biomedical Engineering
• Electrochemistry
• Nanomaterials

Background:

• Accurate detection of low-concentration protein biomarkers like insulin is crucial for disease diagnostics but remains challenging.
• Existing methods often lack the required sensitivity, stability, and selectivity.
• Developing reliable biosensors for early disease detection is a significant unmet need.

Purpose of the Study:

• To develop a sensitive and selective method for detecting low levels of insulin in human serum.
• To utilize silver nanoflower (AgNF)-decorated reduced graphene oxide (rGO) composite material for enhanced biosensing capabilities.
• To establish a quantitative detection range and assess the performance in both phosphate-buffered saline (PBS) and human serum.

Main Methods:

• Fabrication of micro-disk electrode arrays (MDEAs) modified with AgNF-rGO composite.
• Characterization of the AgNF-rGO composite using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy.
• Electrochemical impedance spectroscopy (EIS) was employed to quantify insulin concentration via changes in impedance (ΔZ) in a [Fe(CN)6](3-/4-) redox system.

Main Results:

• The AgNF-rGO hybrid interface demonstrated enhanced electrical conductivity and improved antibody-antigen binding capacity.
• The developed electrode showed a quantitative response to insulin over a working range of 1-1000 ng mL(-1).
• Achieved detection limits of 50 pg mL(-1) in PBS and 70 pg mL(-1) in human serum.

Conclusions:

• The AgNF-rGO/MDEAs platform provides a highly sensitive and selective approach for insulin detection.
• This methodology holds promise for reliable and stable disease diagnostics, particularly for conditions related to insulin levels.
• The enhanced electrochemical properties of the composite material are key to its superior biosensing performance.