title: Using gold nanoclusters as selective luminescent probes for phosphate-containing metabolites.
abstract: Glutathione-bound gold nanoclusters (AuNCs@GSH) can emit reddish photoluminescence under illumination of ultraviolet light. The luminescence of the AuNCs@GSH is quenched when chelating with iron ions (AuNCs@GSH-Fe(3+)), presumably resulting from the effective electron transfer between the nanoclusters and iron ions. Nevertheless, we found that the luminescence of the gold nanoclusters can be restored in the presence of phosphate-containing molecules, which suggested the possibility of using AuNCs@GSH-Fe(3+) complexes as the selective luminescent switches for phosphate-containing metabolites. Phosphate-containing metabolites such as adenosine-5'-triphosphate (ATP) and pyrophosphate play an important role in biological systems. In this study, we demonstrated that the luminescence of the AuNCs@GSH-Fe(3+) is switched-on when mixing with ATP and pyrophosphate, which can readily be observed by the naked eye. It results from the high formation constants between phosphates and iron ions. When employing fluorescence spectroscopy as the detection tool, quantitative analysis for phosphate-containing metabolites such as ATP and pyrophosphate can be conducted. The linear range for ATP and pyrophosphate is 50 μM to sub-millimolar, while the limit of detection for ATP and pyrophosphate are ∼43 and ∼28 μM, respectively. Additionally, we demonstrated that the luminescence of the AuNCs@GSH-Fe(3+) can also be turned on in the presence of phosphate-containing metabolites from cell lysates and blood plasma.
authors: Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
authors: Po-Han
authors: PH
authors: Li
authors: Ju-Yu
authors: JY
authors: Lin
authors: Cheng-Tai
authors: CT
authors: Chen
authors: Wei-Ru
authors: WR
authors: Ciou
authors: Po-Han
authors: PH
authors: Chan
authors: Liyang
authors: L
authors: Luo
authors: Hung-Yu
authors: HY
authors: Hsu
authors: Eric Wei-Guang
authors: EW
authors: Diau
authors: Yu-Chie
authors: YC
authors: Chen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002412:Cations / Q000737:chemistry; D002460:Cell Line; D005978:Glutathione / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007501:Iron / Q000737:chemistry; D057230:Limit of Detection; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010710:Phosphates / Q000032:analysis* / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D002412:Cations; D049408:Luminescent Agents; D010710:Phosphates; D006046:Gold; D000255:Adenosine Triphosphate; D007501:Iron; D005978:Glutathione