Silica nanoparticle-modified paper strip-based new rhodamine B chemosensor for highly selective detection of copper ions in drinking water.

A new rhodamine B derivative (RDB) was synthesized and utilized for the colorimetric detection of copper ions (Cu). This chemosensor utilized a paper strip as a support and a smartphone as a detector for on-site quantitative detection of Cu in water samples. Silica nanoparticles (SiNPs) were investigated as the modifier nanoparticles to achieve uniform color on the paper strip and showed a color response 1.