A Highly Selective Rhodamine Based Colorimetric Sensor Toward Cu2+

A probe for recognition of Cu2+ was developed based on rhodamine B. The probe was synthesized by condensation between rhodamine B and quinoline-2-carbaldehyde. The probe exhibits highly selectivity toward Cu2+ detection. It binds Cu2+ in a 1:1 stoichiometry in acetonitrile solution. Distinct color change can be observed upon the addition of Cu2+ and little interference with other biologically relevant metal ions. Only Fe3+ addition shows a little disturbance in absorption enhancement. In addition, the limit of detection toward Cu2+ is about 235times lower than the World Health Organization (WHO) recommended level in drinking water.