Reversible and Sensitive Hg²⁺ Detection by a Cell-Permeable Ytterbium Complex

Abstract

A cell-permeable ytterbium complex shows reversible binding with Hg in aqueous solution and in vitroby off-on visible and NIR emission. The fast response and 150 nM sensitivity of Hg detection is based upon FRET and the lanthanide antenna effect. The reversible Hg detection can be performed in vitro, and the binding mechanism is suggested by NMR employing the motif structure in a La complex and by DFT calculations.

A stoichiometric terbium-europium dyad molecular thermometer: energy transfer properties

“…Ligand 2 (cyclen 1,10-phenanthroline) was prepared by a substitution reaction of 2-bromoacetyl bromide with 1,10-phenanthrolin-5-amine in the presence of K 2 CO 3 in DCM for 22 h to give 1 , which was followed by coupling with a triarmed cyclen in MeCN in the presence of NaHCO 3 at room temperature, giving 2 in a 95.8% yield. The triarmed cyclen 1 was prepared via two-step substitution reactions according to the literature 13 . Complexes 3 (cycLn 1 -phen) were formed by coordinating lanthanide chlorides with one equivalent of ligand 2 in a mixed solution of MeOH and H 2 O at room temperature, followed by precipitation with diethyl ether from methanol.…”

“…Materials containing two different lanthanide ions are attractive for the construction of a self-referencing thermometer 10 . Lanthanide luminescent materials have sharp emission bands 11 , 12 and a large energy shift between the antenna absorption and lanthanide emission 13 , which distinguishes them from other luminescent materials, such as organic dyes or quantum dots 14 . In addition to these properties, lanthanide luminescence has a long lifetime, allowing time-gated techniques to increase the signal-to-noise ratio 15 .…”

Remote Control of Near Infrared Emission with Lanthanide Complexes

“…Mercury(II) sensing could also be demonstrated by Jin, Tanner, Wong et al ., [27] with a scaffold combining a cationic cyclen based ytterbium complex linked to a carbodithioate‐rhodamine sensing unit. Both rhodamine visible emission at 596 nm and ytterbium based NIR emission at 980 nm are observed upon UV excitation, and are enhanced upon the addition of Hg(II) and the opening of the rhodamine unit.…”

Highly luminescent, biocompatible ytterbium(iii) complexes as near-infrared fluorophores for living cell imaging

“… 28 Pecoraro, Petoud and coworkers demonstrated Ln 3+ (Ln = Nd, Yb) encapsulated sandwich metallacrowns for combined cell fixation and counter staining 29 and necrotic cell imaging. 30 Wong and co-workers also prepared a series of NIR emissive Yb 3+ complexes 31 – 33 and Yb 3+ porphyrinate with conjugated rhodamine B for two-photon living cell imaging but in the visible region. 34 The features of NIR Ln complexes including large Stokes shifts, characteristic elemental emissions 35 – 38 and long decay lifetimes 39 – 41 render them complementary to organic fluorophores, but the low quantum yield (<2.5%) 25 – 34 arising from the forbidden f–f transitions and quenching effect of the high vibration X–H bond (X = C, N and O) is still a general issue remaining to be addressed.…”