Multiple Stimulus Response Material Based on Sr-tcbpe MOF for Mechanochromism, Visualization Labeling, and Etching Toward TNP.

The abuse and excessive discharge of organic pollutants such as nitroaromatic compounds (NACs) have become a hot topic of concern for all humanity and society, and the development of fast, effective, and targeted technical means for detecting NACs also faces many challenges. Here, we reported a strontium-based metal-organic framework (MOF) {[Sr(tcbpe)(HO)]} (), in which tcbpe represents deprotonated 4',4‴,4″‴,4‴‴-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1'biphenyl]-4-carboxylic acid)). In , Sr-O polyhedron and deprotonated tcbpe ligand have a staggered connection to form a self-assembled three-dimensional network structure. In addition, it is found that undergoes no luminescent color change when grinding under solvent protection, while mechanochromic fluorescence behavior is observed when grinding directly, leading to luminescent color changes from cyan to green (). Additionally, and could selectively detect PNP, DNP, and TNP, and achieves visual fluorescence sensing detection toward TNP at a limit of detection as low as 2.25 μM. Moreover, during the detection process, unexpectedly, TNP exhibits a selective etching effect on , which could drill nano holes with different sizes on the surface area of MOF materials to a certain extent, achieving the conversion of chemical energy to mechanical energy. In addition, the successful preparation of a portable sensor @gypsum block provides a platform for the perfect combination of mechanochromic fluorescence behavior and visualization detection toward TNP. It lays the foundation for the practical application of MOF materials in daily life.