*2.3.1.1.4 Biosensors for cancer applications*

The use of biosensors in cancer diagnostics has a lot of promise. Cancer is the second biggest cause of mortality [71], and because biomarker concentrations in the early stages of tumor formation are relatively low, biosensor sensitivities or their LODs are critical for early diagnosis [72]. Early diagnosis of malignant cells before they spread has been shown to improve treatment outcomes and save lives. As a result, specialized, accurate, and rapid-response biosensors are in high demand in oncology, some of which can be seen in **Figure 11**. Recent biosensor advancements have greatly improved breast cancer diagnosis [74]. Breast cancer is the second most frequent cancer in women in the United States, after skin cancer, and the second most lethal, after lung cancer [75]. Traditional breast cancer diagnostic methods such as mammography, magnetic resonance imaging, and enzyme-linked immunosorbent assays (ELISAs) have produced impressive results; however, many false-negative or false-positive results continue to occur, and the adverse effects of some invasive techniques necessitate the development of new highly sensitive, reliable, and noninvasive methods for detection and prognosis [74].
