The smartphone has long been replaced by many users with an audio player, camera, recorder, compass and notebook. All the most important things are now combined in one portable device, but manufacturers are trying to expand its list of features. Now the eyes of companies are focused on the symbiotic fusion of medical devices with mobile gadgets. So, researchers from the University of California decided to add a new function to the case for a smartphone – the determination of blood glucose. A sample of the unusual GPhone case was printed on a 3D printer. The prototype works due to the battery of the smartphone on which it is installed. At the edge of the case there is a replaceable reusable sensor that is connected to the printed circuit board. There is also a stylus with thirty disposable pellet balls. To determine the level of glucose in the blood, it is necessary to touch the sensor with a stylus (thereby recharging it), and then add a few drops of blood to the pellet. The glucose oxidase enzyme, built in, begins to respond to the amount of glucose and delivers an electronic signal that is received by the sensor electrodes. Data from the case is transmitted via Bluetooth to the special application of the Android smartphone. The received information can be stored for monitoring and reporting to the attending physician. The test itself takes approximately 20 seconds. After the procedure, the pellet is sent to the trash, and the sensor turns off independently. New technology is still under development. The results of the work can be found in the publication “Biosensors and Bioelectronics” (Biosensors \u0026 Bioelectronics). Now scientists are working to reduce the amount of blood required for the test (currently it is about 12 drops). According to the developers, GPhone has huge potential. It can be used to monitor other health indicators using pellets with granules of other enzymes. At the same time, disposable pellets will cost no more than a strip designed for a standard test for determining blood glucose levels. In the future, the proposed technology is hoped to be built directly into the smartphone.