Highly sensitive and selective turn-on fluorescent chemosensor for Hg2+ in pure water based on a rhodamine containing water-soluble copolymer

A novel easily available turn-on fluorescent polymeric chemosensor poly(VP-co-GMA-g-RhBH) based on water-soluble copolymer with pendant rhodamine B moiety was synthesized, which showed highly selective and sensitive recognition toward Hg2+ in pure water over a wide range of tested metal ions with remarkably enhanced fluorescent intensities and also clear color changes from colorless to pink. In addition, the response of poly(VP-co-GMA-g-RhBH) to Hg2+ is very quick without any time delay. The combination of water solubility and positive fluorescence response as well as color change is hence particularly promising for the practical utility of this sensor.