Despite their great promise and many years of investigation, only a limited number of sensors are commercially available to the public at present.Perhaps the most successful example of such a sensor is the personal glucose meter (PGM), which is widely available in stores and has either saved or improved the quality of lives of millions of diabetic patients worldwide.
However, it can only detect a single target, blood glucose. The personal glucose meter (PGM) is a successful device for point-of-care testing, which has wide accessibility to the public worldwide due to a great deal of advantages including the portable “pocket” size, cost effectiveness, reliable quantitative results and easy operation . However, the application of this successful portable sensor is still limited in its single target (glucose) and its dynamic range of 10–600 mg/dL or 0.6–33 mM glucose . Recently, different approaches have been developed to expand the application of PGM. For example, Xiang and Lu developed some sensors to monitor a series of nonglucose targets by taking advantage of invertaselabeled functional DNAs and antibodies.