Exploring the Ability of Luminescent Metal Assemblies to Bind and Sense Anionic or Ionizable Analytes A Ru(phen)2bipy-Based Dizinc Complex for Bisphenol A (BPA) Recognition.

Luca Conti,Claudia Giorgi,Luca Prodi,Gina Elena Giacomazzo,Giammarco Maria Romano,Andrea Bencini,Liviana Mummolo

doi:10.3390/molecules26030527

Luca Conti, Claudia Giorgi + Show 5 more

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https://doi.org/10.3390/molecules26030527

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Abstract

The synthesis of a new RuII complex, in which the metal is coordinated by two 1,10-phenanthroline ligands and a 2,2′-bipyridyl unit linked, via methylene bridges in its 4 and 4′ positions, to two 1,4,7,10-tetraazacyclododecane (cyclen) macrocycles ([Ru(phen)2L]2+) is reported. Protonation and ZnII binding by [Ru(phen)2L]2+ have been analyzed by potentiometric titration, evidencing the formation of mixed hetero-binuclear and hetero-trinuclear ZnII/RuII complexes. These complexes were tested as bis-phenol A (BPA) binders. Only the dizinc complex with [Ru(phen)2L]2+ is able to bind BPA in aqueous solution, affording a remarkably stable {Zn2[Ru(phen)2L]BPA(H−2)}4+ adduct at neutral pH, in which BPA is bound in its doubly deprotonated form to the two ZnII ions. BPA binding was found to quench the luminescence emission of the RuII(phen)2bipy core. Although the quenching effect is modest, this study demonstrates that appropriately designed dizinc complexes can be used for binding and optical sensing of BPA in water.

Highlights

Bisphenol A (BPA) is used in large amounts in the production of polycarbonates, epoxy resins and thermal paper [1,2,3] and, it is commonly contained in various products for everyday use, such as food contact materials, including packaging, bottles and lacquers coatings for tins, electronic equipment, paper or toys [4,5,6]
The quenching effect is modest, this study demonstrates that appropriately designed dizinc complexes can be used for binding and optical sensing of bis-phenol A (BPA) in water
As for many Endocrine Disrupting Chemicals (EDCs), BPA has been intensively introduced into the environment in the last decades, leading to the exposure of animals and humans to its toxic action

Summary

Introduction

Bisphenol A (BPA) is used in large amounts in the production of polycarbonates, epoxy resins and thermal paper [1,2,3] and, it is commonly contained in various products for everyday use, such as food contact materials, including packaging, bottles and lacquers coatings for tins, electronic equipment, paper or toys [4,5,6]. As for many Endocrine Disrupting Chemicals (EDCs), BPA has been intensively introduced into the environment in the last decades, leading to the exposure of animals and humans to its toxic action In this panorama, in the last few years several approaches have been used to develop efficient tools to bind and/or detect BPA, including Au or silica nanoparticles coupled with aptameric binding sites [12,13,14,15,16], electrochemical biosensors [17,18], and molecular imprinted nanoparticles or polymers [19,20,21]. Co acidic groups, including phenolic OH functions, decreases their p theciorntdaiensparcootuopnleaotfipohnen.oTlich-eOrHeffuonrcetio, nds,ewphricoht, oinnparitnicoipnle,ocfanpghiveeninotelragctrioonus ps, w at awinlittkehraahclytiidnorneosg, peinnHvboolvnvidnaignlugtheaecsac,eropcmtooarutisclitdpesortotaifokanesreocpfeBplaPtoAcr.,ecHaayntdarllosopohwboebeiecrxpapnlodHit/eodrvtπoa-lssuttaaecbkisliin,zgeafford bouthne dcomtopletxh. eOnmthetoathle.r hand, these interactions can be too weak to afford stable host–

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