The sensorcan produce an ultrasensitive electrochemical response to HER2 (detectionlimit: 1 ng/mL), with a detection range of 10 to 100 ng/mL, showinghigh sensitivity and promising potential in screening HER2-positivebreast cancer patients. After a comprehensiveanalysis of these biosensors, most sensors exhibit high sensitivityfor detecting biomarkers and can detect them at quite low concentrations.Due to the different measurement units for the biomarkers, comparingtheir detection limits was difficult. Here, ERBB2 is linked to cancer.