Fluorescence method-based nonlinear hybridization chain reaction for highly sensitive and specific detection of HER2

Human epidermal growth factor receptor 2 (HER2) is a crucial target for the clinical treatment of gastric cancer. The development of non-invasive approaches for dynamically monitoring HER2 expression is urgently required to enhance the effective treatment of gastric cancer. This study aimed to propose a straightforward fluorescence detection method for serum HER2, utilizing a nonlinear hybrid chain reaction (NHCR). Through the introduction of HER2 aptamer, the accurate and sensitive detection of serum HER2 content was realized. In contrast to the conventional hybrid chain reaction (HCR), this method provided significant amplification of fluorescence signals. The fluorescence signal increased with the concentration of HER2 ranging from 0.5 to 90 ng mL ^-1 , achieving a detection limit of 38 pg mL ^-1 . The sensor demonstrated high sensitivity, specificity, and reproducibility in detecting HER2. The successful implementation of the NHCR strategy enables accurate detection of HER2 in human serum, making it highly valuable for clinical applications.