Fluorescence and colorimetric‐based sensing of Hg<sup>2+</sup> and Cu<sup>2+</sup> using rhodamine derivative
Jian‐Peng Hu, Qi Lin, Hong Yao, You‐Ming Zhang, Tai‐Bao Wei
Abstract
Effective and simultaneous detection of multimetal ions has been achieved by a colorimetric and fluorometric sensor ( RA ), which was fabricated between rhodamine hydrazide and 9‐anthraldehyde through a simple Schiff base reaction. Sensor RA provided an effective platform for reliable detection of Hg 2+ with a detection limit as low as 9.978 × 10 −9 and displayed fabulous sensitivity for Cu 2+ with a low limit of detection (LOD) of 4.81 × 10 −8 M of detection limit toward Cu 2+ . Among them, the detection limit for heavy metal mercury ions has reached the ultrasensitive level. The sensing mechanism between RA and metal ions was further confirmed by 1 H NMR and IR titration experiments and high‐resolution mass spectrometry and discussed from a theoretic level based on crystal structures and density functional theory (DFT) calculations. The switch in turn‐on signaling was attributed to the spiro‐lactam and ring‐opened form of RA and was accompanied by significant changes in ultraviolet spectroscopy and fluorescent spectrum.