Protein-templated gold nanoclusters as specific bio-imaging probes for the detection of Hg(ii) ions in in vivo and in vitro systems: discriminating between MDA-MB-231 and MCF10A cells.

Gold nanoclusters (AuNCs) synthesized within a protein (Human Serum Albumin, HSA) template exhibited intense red luminescence accompanied by a quantum yield >10% and remarkable photo and cluster-core stability for a prolonged period (more than a year). These photoluminescent nanoclusters (NCs) were resistant to chemical and thermal perturbations but break down selectively and highly sensitively in the presence of mercury, Hg(ii), ions. The AuNCs were efficient in quantifying Hg(ii) ions in solution as well as bound to the hormone insulin.

Enhanced Luminescent Properties of Photo-Stable Copper Nanoclusters through Formation of "Protein-Corona"-Like Assemblies.

In this study, interactions of synthesized copper nanoclusters (CuNCs) with a model transport protein, human serum albumin (HSA), have been systematically investigated by using various spectroscopic approaches. The interactions give rise to the formation of "protein-corona" like assemblies and the luminescence properties (both steady-state and time-resolved) are enhanced due to gradual adsorption of the protein on the surface of the NCs. The associated thermodynamics and binding parameters have been estimated resorting to luminescent experimental techniques as well as isothermal titration calorimetry (ITC) studies, indicating that every NC is surrounded by (4±1) protein molecules.

Photostable Copper Nanoclusters: Compatible Förster Resonance Energy-Transfer Assays and a Nanothermometer.

To address the concern of material chemists over the issue of stability and photoluminescent (PL) characteristics of Cu nanoclusters (NCs), herein we present an efficient protocol discussing PL Cu NCs (Cu/HSA) having blue emission and high photostability. These PL NCs were illustrated as efficient probes for Förster resonance energy transfer (FRET) with a compatible fluorophore (Coumarin 153). Our spectroscopic results were well complemented by our molecular docking calculations, which also favored our proposed mechanism for Cu NC formation.

Temperature induced morphological transitions from native to unfolded aggregated States of human serum albumin.

The circulatory protein, human serum albumin (HSA), is known to have two melting point temperatures, 56 and 62 °C. In this present manuscript, we investigate the interaction of HSA with a synthesized bioactive molecule 3-pyrazolyl 2-pyrazoline (PZ). The sole tryptophan amino acid residue (Trp214) of HSA and PZ forms an excellent FRET pair and has been used to monitor the conformational dynamics in HSA as a function of temperature.

A new rhodamine based colorimetric 'off-on' fluorescence sensor selective for Pd2+ along with the first bound X-ray crystal structure.

A new fluorescence rhodamine derivative bearing an 8-aminoquinoline moiety has been designed and synthesized for selective sensing of Pd(2+) in the presence of other competing metal ions in aqueous media. Pd(2+) induced spirolactam ring opening of rhodamine is confirmed for the first time by the X-ray crystal structure of the bound Pd(2+)-complex.

A new highly selective, ratiometric and colorimetric fluorescence sensor for Cu(2+) with a remarkable red shift in absorption and emission spectra based on internal charge transfer.

A new 1,8-diaminonaphthalene based ratiometric and highly selective colorimetric "off-on" type of fluorescent probe, receptor 2 has been designed and synthesized that senses only Cu(2+) among the other heavy and transition metal ions examined on the basis of internal charge transfer (ICT). The visual sensitivity of the receptor 2 is remarkable, showing dual color changes from colorless (receptor) to purple followed by blue and a large red shift in emission upon Cu(2+) complexation.

N-(6-{2-[6-(2,2-Dimethyl-propanamido)-2-pyrid-yl]eth-yl}-2-pyrid-yl)-2,2-dimethyl-propanamide.

The title compound, C(22)H(30)N(4)O(2), lies about a crystallographic inversion center. The whole mol-ecule is disordered over two positions with a refined occupancy ratio of 0.636 (10):0.

N-(6-Bromo-meth-yl-2-pyrid-yl)acetamide.

The title acetamide compound, C(8)H(9)BrN(2)O, crystallizes with three crystallographically independent mol-ecules (A, B and C) in the asymmetric unit. In mol-ecule A, the mean plane through the acetamide unit is inclined at a dihedral angle of 4.40 (11)° with respect to the pyridine ring [10.

2,7-Dimethyl-1,8-naphthyridine.

The asymmetric unit of the title compound, C(10)H(10)N(2), contains one half-mol-ecule with the two shared C atoms lying on a twofold rotation axis. The 1,8-naphthyridine is almost planar with a dihedral angle of 0.42 (3)° between the fused pyridine rings.

7-(2,2-Dimethylpropanamido)-2-methyl-1,8-naphthyridin-1-ium chloride monohydrate.

The asymmetric unit of the title compound, C(14)H(18)N(3)O(+)·Cl(-)·H(2)O, comprises a substituted amido-naphthyridine cation, a chloride anion and a water mol-ecule of crystallization. Intra-molecular C-H⋯O hydrogen bonds generate six-membered rings, producing an S(6) ring motif. The amido group is twisted from the naphthyridine ring, making a dihedral angle of 17.

Quinoxaline-2-carbonitrile.

In the title compound, C(9)H(5)N(3), the quinoxaline ring is essentially planar, with a maximum deviation of 0.012 (1) Å. Short inter-molecular distances between the centroids of the 2,3-dihydro-pyrazine and benzene rings [3.