Aspartic acid functionalized water-soluble perylene diimide as ¡°Off-On¡± fluorescent sensor for selective detection Cu²⁺ and ATP

详细信息    查看全文

• 作者：Lina Zhong ; Feifei Xing ; Yueling Bai ; Yongmei Zhao ; Shourong Zhu
• 关键词：Perylene diimide ; On&ndash ; Off ; Fluorescent sensor ; Cu2+ ; ATP
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：115
• 期：Complete
• 页码：370-375
• 全文大小：2265 K

文摘

Aspartic functionalized water-soluble perylene diimide, N,N¡ä-di(2-succinic acid)-perylene-3,4,9,10-tetracarboxylic diimide (PASP) has two absorbance maximums at 527 and 498 nm (¦Å ¡Ö 1.7 ¡Á 10⁴ L cm^?1 mol^?1) and two emission peaks at 547 and 587 nm respectively. Emission intensities decrease with the increase of PASP concentrations in 20-100 ¦ÌM ranges. Spectral titrations demonstrate that each PASP can coordinate to two Cu²⁺ ions in the absence of HEPES buffer. Its stability constant is estimated to be about 1.0 ¡Á 10¹² L² mol^?2 at pH 7.20 and its coordinate stoichiometry increased to 7.5 in the same pH in the presence of HEPES buffer. The emission of PASP will be completely quenched upon formation of Cu²⁺ complex. The lowest ¡°turn-off¡± fluorescence detection limit was calculated to be 0.3 ¦ÌM Cu²⁺. PASP-Cu solution was used as a ¡°turn-on¡± fluorescence biosensor to detect ATP. The sensitivity towards ATP is 0.3 ¦ÌM in 50 mM HEPES buffer at pH 7.20, which is one of the most sensitive fluorescence sensors.