title: Copper quantum clusters in protein matrix: potential sensor of Pb2+ ion.
abstract: A one-pot synthesis of extremely stable, water-soluble Cu quantum clusters (QCs) capped with a model protein, bovine serum albumin (BSA), is reported. From matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, we assign the clusters to be composed of Cu(5) and Cu(13) cores. The QCs also show luminescence properties having excitation and emission maxima at 325 and 410 nm, respectively, with a quantum yield of 0.15, which are found to be different from that of protein alone in similar experimental conditions. The quenching of luminescence of the protein-capped Cu QCs in the presence of very low hydrogen peroxide concentration (approximately nanomolar, or less than part-per-billion) reflects the efficacy of the QCs as a potential sensing material in biological environments. Moreover, as-prepared Cu QCs can detect highly toxic Pb(2+) ions in water, even at the part-per-million level, without suffering any interference from other metal ions.
authors: Department of Chemical, Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Salt Lake, Kolkata, India.
authors: Nirmal
authors: N
authors: Goswami
authors: Anupam
authors: A
authors: Giri
authors: M S
authors: MS
authors: Bootharaju
authors: Paulrajpillai Lourdu
authors: PL
authors: Xavier
authors: Thalappil
authors: T
authors: Pradeep
authors: Samir Kumar
authors: SK
authors: Pal
mesh_terms: D000818:Animals; D002417:Cattle; D003300:Copper / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D007854:Lead / Q000032:analysis*; D010084:Oxidation-Reduction; D011789:Quantum Theory; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D007477:Ions; D014874:Water Pollutants, Chemical; D012710:Serum Albumin, Bovine; D007854:Lead; D003300:Copper; D006861:Hydrogen Peroxide