When the distilled water went to the detection zone, the time of test paper in running buffer was nearly 1 min and the red color of different concentrations of glucose solution can be judged by eyes semiquantitatively or analyzed the pictures taken by camera or cell phone with Quantity One software. In our experimental process, camera and parameters are as follows: Canon 600D digital camera with CMOS sensor (Taiwan, China), maximum resolution5184 × 3456 pixels, programmed auto exposure without flash light, the object distance is 30–40 cm.