Pathogenic bacteria, viruses, and cancer cells can proliferate rapidly or even explosively in the human body, posing a serious threat to human life and health for a long time. Especially at the end of 2019, the global outbreak of novel coronavirus pneumonia has aroused global attention to such major public health emergencies. The rapid detection, diagnosis and treatment of bacteria, viruses and cancer cells play an important role in maintaining human life and health. In addition to conventional medical diagnosis and treatment methods, new sensing technologies based on some functional nanomaterials have shown broad development prospects for the detection of viruses, bacteria, and cancer cells and the treatment of diseases caused by the three.