title: The role of protein characteristics in the formation and fluorescence of Au nanoclusters.
abstract: Protein-encapsulated gold nanoclusters have shown many advantages over other gold nanocluster systems, including green synthesis, biocompatibility, high water solubility, and the ease of further conjugation. In this article, we systematically investigated the effects of the protein size and amino acid content on the formation and fluorescent properties of gold nanoclusters using four model proteins (bovine serum albumin, lysozyme, trypsin, and pepsin). We discovered that the balance of amine and tyrosine/tryptophan containing residues was critical for the nanocluster formation. Protein templates with low cysteine contents caused blue shifts in the fluorescent emissions and difference in fluorescent lifetimes of the gold nanoclusters. Furthermore, the protein size was found to be a critical factor for the photostability and long-term stability of gold nanoclusters. The size of the protein also affected the Au nanocluster behaviour after immobilization.
authors: Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL35487, USA. ybao@eng.ua.edu.
authors: Yaolin
authors: Y
authors: Xu
authors: Jennifer
authors: J
authors: Sherwood
authors: Ying
authors: Y
authors: Qin
authors: Dorothy
authors: D
authors: Crowley
authors: Marco
authors: M
authors: Bonizzoni
authors: Yuping
authors: Y
authors: Bao
mesh_terms: D000588:Amines / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D003545:Cysteine / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008024:Ligands; D053768:Metal Nanoparticles / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D010434:Pepsin A / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012995:Solubility; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D014357:Trypsin / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000588:Amines; D000596:Amino Acids; D001672:Biocompatible Materials; D005290:Ferric Compounds; D008024:Ligands; D011506:Proteins; D014867:Water; C000499:ferric oxide; D012710:Serum Albumin, Bovine; D014443:Tyrosine; D006046:Gold; D014364:Tryptophan; D009113:Muramidase; D014357:Trypsin; D010434:Pepsin A; D003545:Cysteine