Optically active red-emitting Cu nanoclusters originating from complexation and redox reaction between copper(ii) andd/l-penicillamine

Abstract

Despite a significant surge in the number of investigations into both optically active Au and Ag nanostructures, there is currently only limited knowledge about optically active Cu nanoclusters (CuNCs) and their potential applications. Here, we have succeeded in preparing a pair of optically active red-emitting CuNCs on the basis of complexation and redox reaction between copper(ii) and penicillamine (Pen) enantiomers, in which Pen serves as both a reducing agent and a stabilizing ligand. Significantly, the CuNCs feature unique aggregation induced emission (AIE) characteristics and therefore can serve as pH stimuli-responsive functional materials. Impressively, the ligand chirality plays a dramatic role for the creation of brightly emissive CuNCs, attributed to the conformation of racemic Pen being unfavorable for the electrostatic interaction, and thus suppressing the formation of cluster aggregates. In addition, the clusters display potential toward cytoplasmic staining and labelling due to the high photoluminescence (PL) quantum yields (QYs) and remarkable cellular uptake, in spite that no chirality-dependent effects in autophagy and subcellular localization are observed in the application of chiral cluster enantiomer-based cell imaging.

The synthesis of switch-off fluorescent water-stable copper nanocluster Hg2+ sensors via a simple one-pot approach by an in situ metal reduction strategy in the presence of a thiolated polymer ligand template

“…We obtained, in all cases, hybrid CuNCs with intense yellow-green emission (around 535 nm) and high fluorescence QYs, in the region of those obtained by other authors. [42][43][44][45][46][47] As shown in Table 2, no significant changes are observed in the emission band maxima of the nanohybrids with variations in the percentage of thiol present in the polymer or the molecular weight, although these parameters are critical for the obtained QY. The highest fluorescence QY values were obtained for polymers with intermediate thiol content values (6 or 8 mol%) and molecular weights of around 20 kg mol −1 ( Table 2 and Fig.…”

“…Thus, recently, two overviews of the topic have been published. 40,41 Different biomolecules have been tested as stabilizing ligands for red-emitting CuNCs on the basis of complexation and redox reactions between copper(II) and different biomolecules, such as D-penillamine, 14,20,42 glutathione, 2,35 albumin, 18,43 and cysteine. 44,45 In addition to small ligands, macromolecules have been assayed, giving rise to green-emitting CuNCs with polyvinylpyrrolidone, 46 red-emitting CuNCs with β-galactosidase, 21 blue-emitting CuNCs with lysozyme, 47 and blue and yellow-emitting CuNCs stabilized with trypsin.…”

Cation Crosslinking-Induced Stable Copper Nanoclusters Powder as Latent Fingerprints Marker

“…From the FTIR spectra of Cu NCs and Ce-Cu NCs aggregates, the broad peaks around 3000-3500 cm −1 represented -NH-and -OH stretching vibration. -COOH stretching vibration at 1525 cm −1 in Cu NCs was absent after adding Ce 3+ and a signal at 1381 cm −1 corresponding to Ce-O bond appeared in Ce-Cu NCs aggregates (Figure 3c), which indicated that Ce 3+ were likely to anchor themselves to -COOH on the capping ligands of Cu NCs through Ce-O bonding [41,42]. Moreover, the stretching vibration of -COOH at 1397 cm −1 in Cu NCs shifted to a higher wavenumber in Ce-Cu NCs aggregates [42].…”

“…-COOH stretching vibration at 1525 cm −1 in Cu NCs was absent after adding Ce 3+ and a signal at 1381 cm −1 corresponding to Ce-O bond appeared in Ce-Cu NCs aggregates (Figure 3c), which indicated that Ce 3+ were likely to anchor themselves to -COOH on the capping ligands of Cu NCs through Ce-O bonding [41,42]. Moreover, the stretching vibration of -COOH at 1397 cm −1 in Cu NCs shifted to a higher wavenumber in Ce-Cu NCs aggregates [42]. Since Ce 3+ had a low standard electrode potential of −2.32, it could easily become oxidized and donated electron pairs to form coordinate bonds [43].…”

Synthesis of Atom‐Precise Chiral Ag14 Clusters Protected by Penicillamine Ligands

“…In previous studies, many biological molecules, such as DNA, protein, and amino acid, have been utilized as chiral ligands to design and synthesize chiral Au/Ag nanoclusters, due to the potential applications in photo‐ and electrochemistry, biology, pharmacology, and medicine 3b,10. For example, Yan's group reported a novel CD method for probing l ‐cysteine in biological fluids on the basis of the self‐assembly of chiral nanoparticle from Ag(I) and l ‐cysteine .…”