The use of biosensors for cancer clinical testing may increase assay speed and flexibility, enable multi-target analyses and automation, and reduced costs of diagnostic testing. Biosensors have the potential to deliver molecular testing to the community health care setting and to underserved populations. Biosensors are devices used to detect the presence or concentration of a biological analyte, such as a biomolecule, a biological structure, or a microorganism. Biosensors consist of three parts: a component that recognizes the analyte and produces a signal, a signal transducer, and a reader device. Biosensors are used in the food industry to measure carbohydrates, alcohols, and acids, for example, during quality control processes. The devices may also be used to check fermentation during the production of beer, yogurt, and soft drinks. Biosensors are devices comprising a biological element and a physiochemical detector that are used to detect analytes. These instruments have a wide range of applications ranging from clinical to environmental and agricultural. The devices are also used in the food industry.