Recently, autoantibody biomarkers have been reported for early diagnosis of type 1 diabetes (T1D) also known as insulin-dependent diabetes mellitus or juvenile diabetes. Our objective is to design an electrochemical immunosensor to detect glutamic acid decarboxylase antibodies (GADA) from serum as a diagnostic measure for T1D. The sensor is designed on a screen printed eight electrode array (AuSPE) made of gold working electrodes, gold counter electrode, and a silver pseudo reference electrode. Protein A/G coated magnetic beads were used to capture the GADA spiked in 5% human serum samples. The antibody-captured by the magnetic beads were allowed to bind with the surface antigen (GAD-65) immobilized onto the carboxylated graphene oxide modified working electrode surface by carbodiimide chemistry. Both differential pulse voltammetry and Faradaic electrochemical impedance techniques were able to detect ultra-low levels of GADA.

Acknowledgements: We are grateful for the financial support by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health under Award Number R15DK103386.