Lab-in-a-phone: Smartphone-based Portable Fluorometer for pH Field   Measurements of Environmental Water
  A novel portable fluorometer combining the attributes of a smartphone with an easy fit, simple and compact sample chamber fabricated using 3D printing has been developed for pH measurements of environmental water in the field. The results were then compared directly with those obtained using conventional electrode based measurements. 
Md. Arafat Hossain, John Canning, Sandra Ast, Peter J. Rutledge, Teh   Li Yen, Abbas Jamalipour
q-bio.QM