en Research Paper Research Paper <b><font face="TimesNewRomanPS-BoldItalicMT"><font face="TimesNewRomanPS-BoldItalicMT"><p align="left"><font size="2">Abstracts: </font></p><p align="left"><font size="2">nanoparticles. All the extracts were used separately for the synthesis of gold nanoparticles through the reduction of</font></p><p align="left"><font size="2">aqueous AuCl</font></p><p align="left"><font size="2">gold ions to gold nanoparticles. The ethanol extract of black tea and its tannin free ethanol extract produced gold</font></p><p align="left"><font size="2">nanoparticles in the size ranges of 2.5-27.5 nm and 1.25-17.5 nm with an average size of 10 nm and 3 nm, respectively.</font></p><p align="left"><font size="2">The prepared colloid gold nanoparticles, using the ethanol extract of black tea, did not show the appropriate stability</font></p><p align="left"><font size="2">during storage time (24 hours) at 4 </font></p><p align="left"><font size="2">showed no particle aggregation during short and long storage times at the same conditions. To the best of our</font></p><p align="left"><font size="2">knowledge, this is the first report on the rapid synthesis of gold nanoparticles using ethanol extract of black tea and</font></p><p align="left"><font size="2">its tannin free fraction.</font></p></font></font><font face="TimesNewRomanPS-ItalicMT"><font face="TimesNewRomanPS-ItalicMT"><font size="2">In this research the ethanol extract of black tea and its tannin free fraction used for green synthesis of gold</font></font></font><font face="TimesNewRomanPS-ItalicMT"><font face="TimesNewRomanPS-ItalicMT" size="2">4</font></font><font face="TimesNewRomanPS-ItalicMT"><font face="TimesNewRomanPS-ItalicMT"><font size="2">¯. Transmission electron microscopy and visible absorption spectroscopy confirmed the reduction of</font></font></font><font face="TimesNewRomanPSMT"><font face="TimesNewRomanPSMT" size="2">o</font></font><font face="TimesNewRomanPS-ItalicMT"><font face="TimesNewRomanPS-ItalicMT"><font size="2">C. In contrast, gold colloids, which were synthesized by a tannin free fraction</font></font></font></b> Camellia sinensis, Gold nanoparticles, Synthesis, Tannin, Black tea, Chloroauric acid 48 53 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-3-128&slc_lang=en&sid=1 M. Banoee,Z. Ehsanfar 180031947532846001334 180031947532846001334 No N. Mokhtari,M. R. Khoshayand 180031947532846001335 180031947532846001335 No A. Akhavan Sepahi 180031947532846001336 180031947532846001336 No P. Jafari Fesharaki,H. R. Monsef-Esfahani, 180031947532846001337 180031947532846001337 No A. R. Shahverdi shahverd@sina.tums.ac.ir 180031947532846001338 180031947532846001338 Yes