Rhodol-derived turn-on fluorescent probe for copper ions with high selectivity and sensitivity

A new rhodol-derived fluorescent probe 1 with picolinate as the recognition receptor was designed and simply synthesized using a one-step reaction. With the concentration of added Cu²⁺ increases, it gradually turns pink, so the effect of naked eye detection can be achieved. The detection limit of probe 1 for Cu²⁺ is 42 nM, and the linear detection range was 0–2 μM. The experimental results showed that 1 was a fluorescent probe with high selectivity, good water solubility, and high sensitivity to Cu²⁺. Probe 1 was successfully applied in cell imaging experiments and can detect the concentration of Cu²⁺ in water samples. All these indicate that probe 1 has the potential to be applied to the detection of Cu²⁺ concentration in the real environment.