A novel luminescent Pb(ii) – organic framework exhibiting a rapid and selective detection of trace amounts of NACs and Fe3+ with excellent recyclability

Abstract

A novel three-dimensional metal organic framework, Pb₃O₂L (1) (H₂L = 4-(1H-tetrazol-5-yl)phenol), with a unique 3D network structure exhibits excellent luminescence and good stability in water and other organic solvents. 1 can act as a promising dual functional sensor for the detection and recognition of nitroaromatic explosives (NACs) and Fe³⁺ ions via fluorescence quenching with high selectivity and sensitivity in an aqueous phase. Importantly, 1 as a fluorescent sensor of Fe³⁺ can be simply and quickly regenerated, which represents a rare example of a reported luminescent sensor of Fe³⁺ ions. Furthermore, the visible colour changes in the detection process make them easy to distinguish by the naked eyes, and luminescent test plates broaden its potential application in detection of Fe³⁺ ions. Experimental and theoretical calculations indicate that the luminescence quenching can be attributed to an electron and resonance energy transfer between the MOF and analytes. The present study contributes to the development of MOF materials research, specifically in their application as biological and environmental fluorescent sensors.