The performance efficiency of Pt@Cu bimetallic nanosponges in the design of label-free electrochemical immuno- and aptasensors for determination of HER2

Early cancer detection is a crucial step for survival, and the label-free and sensitive detection of human epidermal growth factor receptor 2 (HER2), a key biomarker, is still one of the important research areas in the diagnosis of breast cancer. Here, we reported the development of novel label-free immuno- and aptasensors for HER2 detection based on modified screen-printed electrodes (SPE) with the decoration of platinum and copper bimetallic-based nanosponges (Pt@Cu NSs). The surface of Pt@Cu NSs/SPE has been immobilized by HER2-specific monoclonal antibody (anti-HER2) and aptamer, separately. The analytical performances of both immuno- and aptasensors with their associated HER2 antigen were investigated using the electrochemical impedance spectroscopy (EIS) technique. Both sensors exhibited similar performance under optimal experimental conditions, with a nearly identical limit of detection (LOD) of 30.3 fg mL⁻¹ and 33.3 fg mL⁻¹ for immuno- and aptasensors, respectively, in the range of 0.1–10,000 pg mL⁻¹. The immuno- and aptasensors' results were further verified by detecting spiked HER2 in commercial human serum samples, yielding satisfactory recovery results (aptasensor: 100.16–103.56 %; immunosensor: 103.88–106.40 %) with RSD values below 10 %. The immuno- and aptasensors corroborated good stability, reproducibility, and selectivity as well as were found to be selective toward HER2 in the presence of various interfering agents. Our current findings demonstrate the great potential of our developed immuno- and aptasensors for practical use by combining electrochemical approaches to obtain accurate disease detection with simultaneous use.