Ultrasensitive electroanalytical sensing platform using aptamer-conjugated V₂CT_<i>x</i> MXene for the detection of the HER-2 biomarker

Breast cancer is a leading cause of mortality among women globally, with the human epidermal growth factor receptor-2 (HER-2) serving as a vital biomarker for its diagnosis and management. In this study, an electrochemical aptasensor was developed using V₂CT_<i>x</i> MXene for the sensitive and selective quantification of HER-2. The sensor's electrochemical performance was evaluated through cyclic voltammetry (CV) and square wave voltammetry (SWV) that demonstrated a wide linear detection range of 1 ng mL^-1 to 100 μg mL^-1. The aptasensor achieved an exceptional detection limit of 0.36 ng mL^-1 and a quantification limit of 1.96 ng mL^-1 under optimized conditions. Furthermore, the sensor displayed excellent selectivity for HER-2 against other biomarkers and retained stability for 40 days, making it suitable for prolonged use. The high electrochemical response was attributed to the exceptional surface-to-volume ratio and conductivity of the V₂CT_<i>x</i> MXene, enabling efficient aptamer immobilization and signal enhancement. These findings highlight the potential of the developed aptasensor as a non-invasive, reliable, and cost-effective platform for early HER-2 detection, paving the way for improved breast cancer diagnosis and monitoring.