Disposable POCT Type Sensor for C-reactive Protein Using Extended Gate Field Effect Transistor and Anti-CRP Antibody (2023)

Undergraduate: Varun Kochar

Faculty Advisor: Koji Sode
Department: Biomedical Engineering

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Introduction:

C-reactive protein (CRP) is an acute inflammatory protein which has elevated expression at sites of infection or inflammation. These proteins are synthesized primarily in the liver and exist in the bloodstream. CRP measurement can be useful in predicting development of chronic inflammatory and neurodegenerative diseases such as cardiovascular disease, type 2 diabetes mellitus, Alzheimer’s, and many more. Current sensors rely upon voltametric methods that are expensive, time-intensive, and requiring complex operation. Extended gate field effect transistors offer a promising alternative due to high sensitivity, low cost, and easy integration.

Materials and Methods:

I immobilized CRP Recombinant Rabbit Monoclonal Antibody (1H3L5) on Gold Disk Electrodes with the following method. I polished electrodes with AlO2 powder and cleaned them electrodes with KOH and H2O2. I immobilized anti-CRP IgG on the electrode surface using a DSH self-assembled monolayer, which contains a thiol group attaching to the gold electrode surface, and a succinimide group binding with the primary amine of the antibody. Lastly, I blocked the gold electrode surface with 5% skim milk. I then used these electrodes in an EGFET setup with varying concentrations of CRP for electrochemical measurement.

Results and Discussion:

I was able to perform sensitive measurement of C-reactive protein within the physiological range. EGFET proved to be successful by displaying increases in drain current corresponding to increasing CRP concentrations.

Conclusions:

Electrochemical sensing of CRP was achieved with IgG. Future work will entail a system for continuous monitoring of CRP using EGFET anti-CRP single chain fragment variable.

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