Fe^III–Salen‐Based Probes for the Selective and Sensitive Detection of E450 in Foodstuff

Abstract

Inorganic pyrophosphate( PPi)i sc onsidereda sa diagnostic marker for various diseasess uch as cancer and vascular calcification. PPi also plays an important preservative role as an additiveE 450 in foodstuff. In this work, as elective Fe III -salen-basedp robe for PPi is described;t his probe disassembles in the presence of the target analyte into its molecular blocks, 1,2-propanediamine and 3-chloro-5-formyl-4-hydroxybenzenesulfonic acid. The latter signaling unit leads to afluorometric response. Compared with arelated prototype, the new complex shows a2 .3-times stronger emission at 500 nm and a1 55-times better selectivity of PPi over adenosine triphosphate( ATP). Importantly,t he new probew as successfully applied for detectingE 450 in foodstuff.

Transition metal(II) complexes featuring push-pull dianionic Schiff base ligands: synthesis, crystal structure, electrochemical, and NLO studies

“…This is due to their facile synthesis, structural flexibility, easily tunable electronic properties, associated with their diverse applications in various branches of science [9]. Transition metal complexes of Schiff base ligands [10] have also found applications in many research areas such as catalysis [11][12][13], molecular magnetism [14][15][16][17], sensing [18][19][20], energy materials [21,22], as well as molecular building blocks [23,24], and for their numerous bioactive properties [25][26][27][28][29]. On the other hand, transition metal complexes of Schiff base ligands form also a promising and efficient class of nonlinear optical (NLO) molecular materials [30][31][32][33][34].…”

Induced fit activity-based sensing: a mechanistic study of pyrophosphate detection with a “flexible” Fe-salen complex

“…11,20 The Zelder group and others are interested in the development of activity-based probes to detect and study the roles of phosphates in biological systems, in the environment and in foodstuff. 11,[21][22][23] For this purpose, fluorescent probes are advantageous, but selective sensing of the target analyte in the presence of a pool of related bioavailable, competing phosphates is highly challenging. [24][25][26][27] Genetically encoded and aptamer based systems offer interesting opportunities, [28][29][30] whereas costeffective small-molecular chemical systems are still rare.…”

“…27,31 Two of us introduced Fe-salen complexes for selectively detecting PPi in cancer cells and in foodstuff. 11,21,23 The Fe III complex 1-OH 2 (Figure 1A) exhibits a square pyramidal coordination geometry and is composed of four (i-iv) subunits: 23 a central Fe III -ion (i), a propanediamine backbone (6) (ii), two 3-chloro-5-sulfosalicylaldehyde moieties (4) (iii) and an apical water ligand (iv; Figure 1A). 23 Upon interaction with PPi, the metal complex disassembles and unleashes the fluorescent signaling unit 4 (Figure 1A).…”

“…11,21,23 The Fe III complex 1-OH 2 (Figure 1A) exhibits a square pyramidal coordination geometry and is composed of four (i-iv) subunits: 23 a central Fe III -ion (i), a propanediamine backbone (6) (ii), two 3-chloro-5-sulfosalicylaldehyde moieties (4) (iii) and an apical water ligand (iv; Figure 1A). 23 Upon interaction with PPi, the metal complex disassembles and unleashes the fluorescent signaling unit 4 (Figure 1A). 23 Importantly, discrimination between PPi and other anions including related phosphates such as inorganic phosphate, ATP and ADP was demonstrated.…”

“…23 Upon interaction with PPi, the metal complex disassembles and unleashes the fluorescent signaling unit 4 (Figure 1A). 23 Importantly, discrimination between PPi and other anions including related phosphates such as inorganic phosphate, ATP and ADP was demonstrated. 23 Mechanistic details on the nature of the active species, the molecular recognition and the binding event as well as the irreversible disassembly process have however not been studied so far.…”