Zinc-cyclen coordination to UTP, TTP or pyrophosphate induces pyrene excimer emission

Abstract

Pyrene labelled Zn(2+)-cyclen 1 and bis-Zn(2+)-bis-cyclen 2 complexes were synthesized. The reversible coordination at physiological pH of Zn(2+)-cyclens to phosphate anions and to imide moieties, as present in thymine and uracil nucleotides, is well known. In the presence of analytes bearing a phosphate and an imide or two phosphate groups the formation of a ternary complex consisting of two pyrene-labelled metal complexes and the analyte molecule, is observed. The close proximity of the pyrene labels in the complex induces pyrene excimer emission, which is observable by the unarmed eye. By this, the presence of UMP, UDP, UTP and TTP in buffered aqueous solution is signalled, while other nucleotides are not able to induce excimer emission. In the same way, Zn(2+)-cyclen-pyrene acts as luminescent chemosensor for PP(i) and fructose-1,6-bisphosphate in aqueous buffer.

Experimental and computational thermodynamics of pyrene and 1-pyrenecarboxaldehyde and their photophysical properties

“…Pyrene and its derivatives have been studied intensively as organic chromophores [5,6], sensors [7,8], light emitting materials in OLEDs [9][10][11][12], organic field effect transistors (OFETs) [12,13] and organic photovoltaic devices (OPVs) [12]. Synthetic pyrene-appended systems are used as sensors for ATP [14], heparin [15], nucleotides [16,17], transition metal ions [18] and as probes to study protein conformation, conformational changes, protein folding and unfolding, protein-protein, protein-lipid, and protein-membrane interactions [19]. They also find application as building blocks for preparation of luminescent polymers [20].…”

Supramolecular self-assembly of nucleotide–metal coordination complexes: From simple molecules to nanomaterials

“…For example, Zn 2+ -cyclen-pyrene or bis-Zn 2+ -bis-cyclenpyrene can be used as sensors to differentiate nucleotides(Fig. 17)[174]. Both of these Zn 2+ compounds can interact with phosphate and imide moieties via reversible coordination and form ternary complexes with uracil-and thymine-based nucleotides (such as UTP, UDP, or TTP) in HEPES buffer under physiological conditions.…”

Zn2+-cyclen-based complex enable a selective detection of single-stranded thymine-rich DNA in aqueous buffer

“…Some crystal structures of Zn 2 þ -cyclen complexes with thymine or its analogues revealed a strong coordinate interaction of Zn 2 þ -cyclen with the deprotonated "imide" anion of the thymine group (Shionoya et al, 1993(Shionoya et al, , 1994Gasser et al, 2007). Based on this special recognition, some sensors were developed for detection of thymine derivatives, such as thymidine nucleotides (Kwon et al, 2008;Zeng et al, 2010;Schmidt et al, 2010), thymidilyl(3′-5′)thymidine (Zeng et al, 2009), thymine flipping (O'Neil andWiest, 2005), thymine bulges in DNA (Mundo et al, 2012). However, there is little work to utilize these complexes as fluorescent probes for single-stranded nucleic acids.…”