I. Introduction
With the rapid development of science, technology and economy, people pay more and more attention to their health. Home detection is increasingly accepted, because it enables easy and non-invasive health surveillance under zero psychological pressure [1], [2]. Thus, intelligent and miniaturized sensing devices for home detection [3] attract great attention. A number of sensors have been developed for home detection of body fluids, such as integrated electronic skin to measure metabolites in sweat [4], eyeglass-based tear biosensors to detect alcohol, vitamins and glucose [5], wireless oral biosensor to real-time detect uric acid in saliva [6], and optical urine sensors to measure inorganic ions [7], glucose [8], and drug molecules [9], [10]. Urine, as an information-rich and easily accessible body fluid, shows unique advantages in home detection and is conducive to long-term surveillance of some chronic diseases.