Electrochemical Immunosensor for the Quantification of S100B at Clinically Relevant Levels Using a Cysteamine...

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Neuroscience Diagnostics

Background:

• Traumatic brain injury (TBI) necessitates timely clinical assessment via biomarkers like S100B.
• Current S100B quantification methods (immunoassays) are slow, expensive, and require expertise.
• Development of rapid, accessible diagnostic tools for TBI management is critical.

Purpose of the Study:

• To develop and characterize a novel electrochemical biosensor for S100B quantification.
• To immobilize anti-S100B antibodies onto gold electrodes using a zero-length cross-linking approach.
• To evaluate the performance of planar (AuEs) and interdigitated (AuIDEs) gold electrode platforms.

Main Methods:

• Antibody immobilization on gold electrodes (AuEs and AuIDEs) via cysteamine SAM and carbonyl-bond cross-linking.
• Surface characterization using Atomic Force Microscopy (AFM) and Fourier-Transform Infrared Spectroscopy (FTIR).
• Electrochemical Impedance Spectroscopy (EIS) to measure changes in charge-transfer resistance (Rct) with varying S100B concentrations (10-1000 pg/mL).

Main Results:

• Increased Rct values correlated with higher S100B concentrations on both AuEs and AuIDEs.
• Achieved Limit-of-Detection (LOD) of 18 pg/mL for AuEs and 6 pg/mL for AuIDEs.
• AuIDEs demonstrated simpler fabrication, reduced time/cost, and potential for single-frequency capacitance analysis.

Conclusions:

• The developed electrochemical biosensor, particularly the AuIDE platform, offers a promising rapid detection method for S100B.
• This technology could significantly improve the timely diagnosis and management of TBI.
• The AuIDE biosensor presents a cost-effective and efficient alternative to conventional S100B immunoassays.