Methylated Eu(III) metal-organic framework as a fluorescent probe for constructing molecular logic gates and monitoring of F-, I-, and S2.

Abstract

A novel fluorescent and electron-deficient hybrid, N-methylated [Eu (pddb)phen(ox)0.5]n (Eu-MOF-Me) has been prepared via post-synthetic modification. Considering its special luminescent properties and cationic framework, Eu-MOF-Me is developed as a visualized fluorescent probe. Notably, water-stable Eu-MOF-Me exhibits advantages like good structural and fluorescent stability in a wide range of pH value (3.39-10.86), excellent identification ability for F-, I-, and S2- (it can easily distinguish F- and I- from otherhalogen ions and can realize naked eye identification of F-, I-, and S2-), relatively low detection limits (6.61μM for S2-, 7.57μM for F-), and reusability. More importantly, it has been utilized for the construction of a Boolean logic gate system. In this system, Eu-MOF-Me serves as the gate, by taking F-, I-, and S2- as the inputs and fluorescence emission bands (UV380, B437, and R612) as the outputs; some primary logic gates (NOR, IMP, YES, NOT) and the combination of them have been realized. Moreover, we achieved a cascaded logic gate (NOR+OR). For further application, a molecular computing keypad-lock security system has beenobtained. Graphical abstract A novel fluorescent and electron-deficient hybrid named Eu-MOF-Me has been prepared via post-synthetic methylation. Considering its special luminescent properties and cationic framework, Eu-MOF-Me was developed as a fluorescent probe for the visual monitoring of important anions. In addition, it was used for the construction of Boolean logic library and a keypad-lock system was achieved.