Identification of S-phenylmercapturic acid using heterometallic Zn–Eu MOF as a Fluorescence sensor

Abstract

S-phenylmercapturic acid (S-PMA) can be served as an important biomarker for detecting benzene metabolites in clinical diagnosis. In this work, a 3D luminescent heterometal-organic framework (HMOF) with two kinds of pores was designed and synthesized by choosing d/f heterometals salts and two ligands with abundant coordination sites, {[EuZn2(imdc)2(bpe)(H2O)3(OH)]·bpe}n (H3imdc = 1H-imidazole-4,5-dicarboxylic acid; bpe = 1,2-bis (4-pyridyl)-ethylene), namely, MOF 1, which could be utilized to selectively recognize S-PMA by the fluorescence quench. It demonstrated that an efficient recoverable luminescent probe MOF 1 had determined S-PMA with excellent sensitivity (the limit of detection = 3.0 × 10-8 M), rapid response time (less than 20 s), and a wide linear concentration range (3.70 ∼ 180 µM). More interestingly, this is the first instance of utilizing a luminescent MOF for the detection of S-PMA. A low-cost portable composite film for the convenient detection of S-PMA had been designed to recognize S-PMA by visual changes in luminescent color. In addition, the fluorescence sensing mechanism of S-PMA by MOF 1 was elaborated.