New colorimetric chemosensor based on rhodamine hydrazide to detect Cu2+ ions by naked eye

A rhodamine-based chemosensor for naked-eye detection of Cu 2+ has been designed and synthesized, which exhibited excellent selectivity and high sensitivity for Cu 2+ in CH 3 CN and CH 3 CN/H 2 O mixed solutions. When Cu 2+ was added to the solution of sensor 1 , a dramatic color change from colorless to bluish violet was observed, while the cations K + , Ca 2+ , Na + , Hg 2+ , Zn 2+ , Co 2+ , Ni 2+ , Fe 3+ , Al 3+ , Pb 2+ , Ag + , and Cd 2+ did not interfere with the recognition process for Cu 2+ . The pH effect investigations indicated that it can be applied to analysis of samples over a wide pH range.