Sensitive electrochemical detection of DR1 based on gold nanoparticle-modified MoS2 and hyaluronic acid-based thionine

The analysis of down-regulator of transcription 1 (DR1) offers significant information for the rapid and non-invasive diagnosis of Hashimoto's thyroiditis (HT). In this study, we report a novel dual-signal amplification electrochemical biosensor for the sensitive detection of DR1. Gold nanoparticle (AuNP)-modified molybdenum disulfide (MoS₂@AuNPs), which has extremely strong electron transfer ability and abundant binding sites, is first modified on an electrode surface as a substrate material to implement the first signal amplification. After the formation of the sandwich structure based on the specific recognition of antigens and antibodies, the electroactive molecules hyaluronic acid-based thionine (HA@Thi) are introduced to achieve the second signal amplification. Using this dual-signal amplification strategy, the proposed biosensor achieves a linear range of 1 × 10⁻⁴–1 × 10² ng mL⁻¹ with a low detection limit of 10.99 fg mL⁻¹. In addition, the electrochemical biosensor has high selectivity and good stability, and is applicable to the assay of DR1 in the presence of complex biological matrices, which is expected to provide a scientific approach for the clinical application of serum DR1 monitoring. More importantly, our method may extend the application of protein-based biosensors in disease diagnosis techniques.