An electrochemical biosensor using AuNPs-Ti3C2Tx and ARGET ATRP reactions as signal amplification strategies for ultra-sensitive detection of HER2 protein

Human epidermal growth factor receptor 2 (HER2) status is an important factor in evaluating the prognosis of breast cancer patients. Therefore, it is particularly important to develop a simple and sensitive method for the detection of HER2-positive breast cancer. Here, an ultra-sensitive electrochemical biosensor for detecting HER2-specific proteins was assembled using gold nanoparticles and Two-dimensional carbides (AuNPs-Ti₃C₂Tx) as a conducting substrate. The prepared AuNPs-Ti₃C₂Tx not only has good electrical conductivity and strong electrochemical signal output, but also provides a large number of active sites for the AuS bonds assembly aptamer. In addition, the antibodies-modified functionalized graphene oxide (GO) as a carrier platform, which provides an additional boost for the detection of trace targets with high sensitivity under optimal conditions. Afterwards,HER2 protein was detected by signal amplification effect of AuNPs-Ti₃C₂Tx and functionalized GO combined with Electron transfer activated regeneration catalyst atomic transfer radical polymerization (ARGET ATRP). In the range of 1 to 10⁵ ng·mL⁻¹, there was a good linear relationship between the HER2 concentration and the signal intensity, with a limit of detection of 0.19 pg·mL⁻¹. Moreover, this method has good selectivity and stability, and then still maintains good detection performance and strong anti-interference ability in the complex environment of normal human serum, which is expected to be applied in clinical application.