Smartphone-based simple and stable digital imaging colorimetric method for the detection of silver ion in effluent

Silver is widely used, but the pollution caused by silver ions is also a problem that cannot be ignored. Detection of heavy metal ions based on bulky and costly analytical instruments had been developed very maturely in the laboratory. At present, the main detection methods of silver ion concentration include inductively coupled plasma mass spectrometry, atomic absorption spectrometry and inductively coupled plasma/atomic emission spectrometry. However, these testing methods have many problems to be solved, such as the high of instruments, high operating cost, numerous operational requirements, long testing time and complex processing technology. Nowadays, with the rapid and powerful development of smartphone technology, the new analytical methods based on smartphones equipped with a camera are being carried in the certain applied ideas. Here, the paper introduces a hand-held detection platform smartphone-based that allows the quantification of silver(I) ions with the detection limit of 0.659 mM. The Colour Grab software of android smartphone was applied to obtain R, G, B values of the photo of Rhodamine B solution remaining fluorescence, and then calculated the corresponding grey values by grey formula. The detection platform based on smart phones has the characteristics of cost-effective design and simple operation, as well as high sensitivity and selectivity. Therefore, compared with other detection methods, this method can be widely and conveniently applied to the detection of silver ions in the environment.