Sensitive Electrochemical Detection of DR1 Based on Electrodeposit AuNPs-Poly(thiophene-3-acetic acid) and Copolymer PLGA

The sensitive detection of down-regulator of transcription 1 (DR1) provides important information for early noninvasive diagnosis and treatment of Hashimoto thyroiditis (HT). In this study, a label-free electrochemical biosensor for DR1 detection was constructed based on electrodeposited gold nanoparticles (AuNPs) and poly(lactic-co-glycolic acid) (PLGA). The AuNPs were first modified to the electrode surface by electrodeposition to increase the specific surface area of the electrode, thus loading more target molecules to increase the sensitivity of the sensor. Then, a sandwich structure was formed on the electrode surface based on the specific recognition of antigen and antibody. PLGA was fixed on the electrode surface by binding with antibody 2 (Ab2) through amide bond to further improve the sensitivity of the sensor. Induced by the dual signal amplification, the sensor has a linear detection range of 50 fg·ml−1 to 50 ng·ml−1, with a detection limit as low as 19.4 fg·ml−1. Moreover, the sensor has good selectivity, specificity, and anti-interference capability, which holds great potential for the early diagnosis of HT and analysis of other disease markers.