SERS-based detection of early Type 1 diabetes mellitus biomarkers: Glutamate decarboxylase antibody and insulin autoantibody

Glutamate decarboxylase antibody (GADA) and insulin autoantibody (IAA) are essential biomarkers for type 1 diabetes mellitus (T1DM). These islet autoantibodies are present in the serum of patients and are useful for the early diagnosis of T1DM. In this study, we developed a surface-enhanced Raman scattering (SERS)-based immunoassay for the detection of two T1DM-related autoantibodies, GADA and IAA. GADA and IAA are specifically captured by their antigens immobilized on the mercaptobenzoic acid (MBA)-functionalized silver substrates. They can be quantitatively detected based on the Raman frequency shifts of the cross-linker MBA. Combined with a 96-well plate, the immunoassay enabled a high-throughput analysis of the two biomarkers. The results suggest that the proposed method has significant potential for clinical application in rapid, sensitive, and high-throughput screening of T1DM.