%0 Journal Article
%T Photoluminescent Gold Nanoclusters as Sensing Probes for Uropathogenic Escherichia coli
%A Po-Han Chan
%A Bhaswati Ghosh
%A Hong-Zheng Lai
%A Hwei-Ling Peng
%A Kwok Kong Tony Mong
%A Yu-Chie Chen
%J PLOS ONE
%D 2013
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0058064
%X Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we demonstrated a facile approach for generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used as sensing probes for corresponding target bacteria. Mannose-capped AuNCs (AuNCs@Mann) were generated and used as the model sensors for target bacteria. A one-step synthesis approach was employed to generate AuNCs@Mann. In this approach, an aqueous solution of tetrachloroauric acid and mannoside that functionized with a thiol group (Mann-SH) was stirred at room temperature for 48 h. The mannoside functions as reducing and capping agent. The size of the generated AuNCs@Mann is 1.95¡À0.27 nm, whereas the AuNCs with red photoluminescence have a maximum emission wavelength of ~630 nm (¦Ëexcitation = 375 nm). The synthesis of the AuNCs@Mann was accelerated by microwave heating, which enabled the synthesis of the AuNCs@Mann to complete within 1 h. The generated AuNCs@Mann are capable of selectively binding to the urinary tract infection isolate Escherichia coli J96 containing the mannose binding protein FimH expressed on the type 1 pili. On the basis of the naked eye observation, the limit of detection of the sensing approach is as low as ~2¡Á106 cells/mL.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0058064