Determination of antibodies against human growth hormone using a direct immunoassay format and different...

Area of Science:

• Electrochemistry
• Biosensors
• Immunotechnology

Background:

• Development of sensitive and accurate methods for detecting specific antibodies is crucial in diagnostics.
• Surface Plasmon Resonance (SPR) and Atomic Force Microscopy (AFM) are established techniques for analyzing biomolecular interactions.
• Electrochemical immunosensors offer potential for sensitive and cost-effective analyte detection.

Purpose of the Study:

• To investigate the applicability and sensitivity of various electrochemical techniques for developing an accurate immunosensor.
• To detect specific antibodies against human growth hormone (anti-hGH).
• To compare the performance of Pulse Amperometry (PA), Cyclic Voltammetry (CV), Square Wave Voltammetry (SWV), and Differential Pulse Voltammetry (DPV).

Main Methods:

• A direct immunoassay format was employed using human growth hormone (hGH) immobilized on a self-assembled monolayer modified SPR chip.
• Electrochemical techniques including PA, CV, SWV, and DPV were utilized for anti-hGH detection.
• SPR and AFM were used as control methods to confirm antigen-antibody complex formation.

Main Results:

• Pulse Amperometry (PA) and Cyclic Voltammetry (CV) exhibited higher sensitivity compared to SWV and DPV.
• The analytical signal obtained with PA was 2.50 times higher than CV, 16.3 times higher than SWV, and 24.5 times higher than DPV.
• The limit of detection for the PA method was 75 nM, which is lower than the 108 nM limit of detection for the CV method.

Conclusions:

• Pulse Amperometry is the most sensitive electrochemical technique for the developed anti-hGH immunosensor.
• The developed electrochemical immunosensor shows high potential for accurate and sensitive detection of anti-hGH antibodies.
• This approach provides a foundation for advanced electrochemical biosensor development.