A novel fluorescent sensor based on 4-(diethylamino)-2-(hydroxy)-phenyl imine functionalized naphthalimide for highly selective and sensitive detection of CN- and Fe3+

In this work, a novel sensor molecule HB1, based on a 4-(diethylamino)-2-(hydroxy)-phenyl imine functionalized naphthalimide derivative, was successfully designed and synthesized. Interestingly, the HB1 showed fluorescence identification ability for CN- in DMSO/H2O (8:2, v/v) solution. After addition of CN- into the HB1 solution, the fluorescence intensity of HB1 solution could be enhanced obviously. The anti-disturbance experiments demonstrated that other anions could not interfere in the detection of CN-. On the other hand, HB1 was capable of dual-channel (absorption and fluorescence) detection of Fe3+ in DMSO solution. With the addition of various metal ions into the HB1 solution, only Fe3+ induced the fluorescence emission of HB1 solution quenching and the colour change, and other metal ions could not interfere in the detection of Fe3+. The limits of detection (LODs) of HB1 for CN- and Fe3+ were 6.30 x 10(-8) and 3.95 x 10(-8) mol/L, respectively. Importantly, the real sample experiment was carried out by detecting CN- in bitter almonds. Additionally, ion test strips based on HB1 were fabricated, which could act as convenient and efficient test kits for detecting CN- and Fe3+.