Nanosensors and their applications in early diagnosis of cancer

According to WHO and other key statistics, cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020. By identifying cancer early, it is more likely to respond to treatment, resulting in a better chance of survival as well as a lower cost of treatment. Early detection of cancer and avoiding delays in treatment can significantly improve the lives of cancer patients. Nanomaterial-based sensors with the ability to extract and identify tumor-specific biomarkers, circulating tumor cells, or extracellular vesicles secreted by the tumor have the potential to diagnose cancer considerably earlier and enhance patient long-term survival. In this review, we provide the application of nanosensors for the early detection of cancer and the recent techniques for clinically diagnosing cancer patients' biomarker levels. Furthermore, the presented works are compared based on their sensitivity and selectivity in the detection of different kinds of cancer biomarkers.