Lanthanide Luminescence Modulation by Cation–π Interaction in a Bioinspired Scaffold: Selective Detection of Copper(I)

Abstract

A prototype luminescent turn-on probe for Cu(+) (and Ag(+)) is described, harnessing a selective binding site (log Kass = 9.4 and 7.3 for Cu(+) and Ag(+), respectively) based on the coordinating environment of the bacterial metallo-chaperone CusF, integrated with a terbium-ion-signaling moiety. Cation-π interactions were shown to enhance tryptophan triplet population, which subsequently sensitized, on the microsecond timescale, the long-lived terbium emission, offering a novel approach in bioinspired chemosensor design.

Using Native Chemical Ligation for Site‐Specific Synthesis of Hetero‐bis‐lanthanide Peptide Conjugates: Application to Ratiometric Visible or Near‐Infrared Detection of Zn2+

“…Design of hetero-bis-lanthanide peptide Zn 2 + + -responsive probes During the past years, we have described several responsive luminescent probes combining luminescent lanthanides, for their emission properties, and peptides, for their highly specific recognition properties. [30,[40][41][42][43] Especially,w eh aves hown that a classical bba zinc finger peptide with an appended DOTA-Ln 3 + Figure 1. Examples of emission spectrao fTb 3 + ,Eu 3 + ,Yb 3 + ,a nd Nd 3 + with DOTA-monoamide ligands obtained from compounds LZF1 Cs124 j Tb , LZF1 Cs124 j Eu ,and LZF1 NBD j Nd for Tb 3 + ,Eu 3 + ,and Nd 3 + , [30] respectively,and compound LZF3 Anthra j Yb for Yb 3 + (this work).…”

A novel DOTA-like building block with a picolinate arm for the synthesis of lanthanide complex-peptide conjugates with improved luminescence properties

“…Some of the photophysical properties of Ln 3+ complexes mentioned above can be advantageously exploited to design responsive luminescent probes [15,[22][23][24][25][26][27][28][29][30]. The main strategies include (i) the modulation of the antenna effect by modulation of the distance between the antenna and the Ln 3+ [23,[31][32][33] or by modulation of the photophysical properties of the antenna (charge transfer, photoinduced electron transfer …) induced by binding of the analyte or reaction with it [34][35][36][37][38][39] and (ii) the modulation of the non-radiative deactivation by playing with the hydration number or with a remote energy acceptor (quencher or fluorophore) [40][41][42][43][44][45]. Among Ln 3+ , Eu 3+ combines several advantages to design responsive probes operating in biologically relevant conditions [27].…”

Luminescent Zinc Fingers: Zn‐Responsive Neodymium Near‐Infrared Emission in Water

“…Ln 3 + complexesh ave desirable photophysical properties [12] for biological applicationsi ncluding:1)atom-like narrow emissionb ands at fixed wavelengthsi ndependent of experimental conditions and characteristico ft he nature of the Ln 3 + ion, 2) al arge difference betweent he absorption and emission wavelengths preventing self-absorption problemsa nd related quantification,3 )low or no tendencyt op hotobleaching, and 4) long emissionl ifetimes( micro to millisecond range), an advantage that can be used in time-gated detection experiments to suppress backgroundf luorescence of the biological medium (the lifetimes of which extend up to af ew nanoseconds for the longest). [22,23] In order to design a Zn 2 + -responsive probe as arecognition unit, we opted for classical bba zinc finger (ZF) peptides, which have ac onsensus sequenceo ft he form (Tyr/Phe)-Xaa-Cys-Xaa 2/4 -Cys-Xaa 3 -Phe-Xaa 5 -Leu-Xaa 2 -His-Xaa 3 -His, where Xaa can be any amino acid. [15][16][17][18][19] As main reasons, we can cite the limited number of antennae for the sensitization of NIR Ln 3 + luminescence and the efficient quenching of their emissionb yh armonicso fh igh energyO ÀHv ibrations of water molecules.…”

“…[21] We are interested in creatingr esponsive luminescent probest hat combine Ln 3 + ions andp eptides caffolds, inspired by specific binding sites of proteins,t ob enefit from their unique recognition abilities. [22,23] In order to design a Zn 2 + -responsive probe as arecognition unit, we opted for classical bba zinc finger (ZF) peptides, which have ac onsensus sequenceo ft he form (Tyr/Phe)-Xaa-Cys-Xaa 2/4 -Cys-Xaa 3 -Phe-Xaa 5 -Leu-Xaa 2 -His-Xaa 3 -His, where Xaa can be any amino acid. [24] They possess the advantage of selectively binding Zn 2 + among physiological cations [24,25] with their cysteine/histidine residues.W hen bound to Zn 2 + ,t hey adopt ac ompact bba fold (two b-sheets and an a-helix) due to the presence of three conserved amino acids (Tyr/Phe, Phe, and Leu) that constitute ah ydrophobic core within the structure.I nc ontrast, they are rather unfolded in the absence of Zn 2 + ( Figure 1A).…”