Naked-eye-based highly selective sensing of Fe3+ and further for PPi with nano copolymer film

Novel rhodamine and quinoline-functionalized nano film was prepared by copolymerization and electrospinning. Propenyl monomer of rhodamine and quinoline was synthesized and then copolymerized with methyl methacrylate via solution polymerization. This prepared copolymer was electrospun into nano film, as a solid-state sensor, which exhibits highly selective recognition of Fe 3+ ions over various environmentally and biologically relevant metal ions and anions with a distinct color change from colorless to pink in very fast response time (<1   min). The sensor can detect Fe 3+ quantitatively in concentration range of 100–2000   μM, and the calculated low detection limit (LOD) value could be 1.19   μM for Fe 3+ . As the resultant product, the Fe 3+ -contaminated nano film showed recovered color change by extra addition of pyrophosphate P 2 O 7 4− (PPi) solution. It was found that the absorption intensity at 564   nm of the Fe 3+ -contaminated nano film linearly decreases with PPi concentration from 50 to 3000   μM with LOD value of 1.75   μM. In addition, both the nano films before and after Fe 3+ -contaminating are reusable for the detection of Fe 3+ and PPi, respectively.