A novel rhodamine B-based “off-on'' fluorescent sensor for selective recognition of copper (II) ions

Fluorescence sensor RBH was developed and synthesized by rhodamine B with 3-methyl-2-benzothiazolinone hydrazine. The sensor showed an off-on response with the addition of copper(II) ions and exhibited high selectivity over other ions which could be due to the ring-opening of rhodamine B derivative closed spirolactam and form the 1:1 complex with Cu2+ ions.96