A novel electrochemical biosensor based on WO3@AuNPs and HBP@BIBB macromolecule-triggered ATRP for DR1 detection

The sensitive detection of down-regulator of transcription 1 (DR1) plays an important role in the early diagnosis and treatment of Hashimoto's thyroiditis (HT). Herein, we report a novel electrochemical sensor based on the nanocomposite of tungsten oxide–gold nanoparticles (WO3@AuNPs) and hyperbranched polymer–2-bromo-isobutyryl bromide (HBP@BIBB) initiated atom transfer radical polymerization (ATRP) for the ultrasensitive assay of DR1. Monolayer WO3 nanosheets, which have high conductivity, were first compounded with AuNPs to obtain the WO3@AuNP nanocomposite. WO3@AuNPs can not only increase the conductivity of the electrode but also provide more active sites for biological molecules, thereby effectively amplifying the output signal. By introducing macroinitiator HBP@BIBB into the ATRP reaction, more electroactive molecules were introduced into the sensor, further amplifying the output signal and making the sensor ultra-sensitive. The optimized sensor demonstrated a wide linear range of 1 × 10−4 –1 × 102 ng mL−1 with a low detection limit of 2.91 fg mL−1. Moreover, the electrochemical biosensor has high selectivity, good stability, and strong anti-interference ability, and is suitable for the determination of DR1 in complex biological matrices. In conclusion, this electrochemical biosensor shows great potential in biomarker detection.