With the rapid development of sensors and biosensors and the advent of smartphones, smartphone-based sensing systems have emerged as new devices for detecting various analytes. These devices take advantage of both the high sensitivity of sensors and biosensors and the variety of functions of smartphones, which can be considered as fast, low-cost, and convenient alternative analytical devices. In biomedical applications, the device has two main parts. The first part includes a sensor (wearable or implantable sensor) for the noninvasive diagnosis of biomarkers in the skin or in various biological fluids. Then, the received signal is ready for wireless or Bluetooth transmission through amplifier, filtering, and digitalization circuits to the patient’s mobile phone, which is the second part of the designed system. These signals are stored and processed and displayed on the mobile screen. Also, smartphones have enabled the miniaturization of sophisticated analytical instruments for different purposes. This chapter summarizes the recent application of smartphones for the development of miniaturized analytical devices.
