An ultra-sensitive and rapid immunosensor for the onsite detection of circulating tumor DNA in breast cancer.

Breast cancer currently stands as the most prevalent form of cancer worldwide and the primary cause of cancer-related deaths among women. However, the current diagnostic methods for breast cancer exhibit several limitations, including invasiveness, high costs, and limited sensitivity and specificity. The detection of the PIK3CA-H1047R variant is of paramount importance due to its close association with tumor growth and treatment resistance. Consequently, developing a straightforward, rapid, and highly sensitive approach for detecting PIK3CA-H1047R is of utmost importance. We have been working on the development of a rapid and ultrasensitive biosensor, leveraging the alternating current (AC) electrokinetic (ACEK) capacitive sensing method. This biosensor involves modifying the surface of interdigital electrodes with antibodies, facilitating the antibody-antigen-binding process through AC electrokinetic techniques. Our sensor strategy directly measures the interface capacitance, and the rate of change serves as a quantitative marker for event identification. Remarkably, our biosensor successfully detects the PIK3CA-H1047R antigen within a concentration range of 1 ng/mL to 1 μg/mL. In conclusion, this study proposes a fast and highly sensitive biosensor for the detection of a key breast cancer marker, the PIK3CA-H1047R variant. This technology is expected to improve breast cancer diagnosis, address the limitations of current methods, and provide patients with better treatment options. This detection method offers a promising avenue for on-site and real-time sensitive detection of the PIK3CA-H1047R antigen, potentially revolutionizing breast cancer diagnosis.