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Biothiols as Chelators for Preparation of N‑(aminobutyl)-N-(ethylisoluminol)/Cu2+ Complexes Bifunctionalized Gold Nanoparticles and Sensitive Sensing of Pyrophosphate Ion
journal contribution
posted on 2014-10-22, 00:00 authored by Fang Li, Yating Liu, Meng Zhuang, Hongli Zhang, Xiaoying Liu, Hua CuiIn
this work, chemiluminescence (CL) reagent and catalyst metal ion complexes
bifunctionalized gold nanoparticles (BF-AuNPs) with high CL efficiency
were synthesized via an improved synthesis strategy. Biothiols, such
as cysteine (Cys), cysteinyl-glycine (Cys-Gly), homocysteine (Hcy),
and glutathione (GSH), instead of 2-[bis[2-[carboxymethyl-[2-oxo-2-(2-sulfanylethylamino)ethyl]amino]ethyl]amino]acetic
acid (DTDTPA), were used as new chelators. N-(aminobutyl)-N-(ethylisoluminol)
(ABEI) was used as a model of CL reagents and Cu2+ as a
model of metal ion. In this strategy, biothiols were first grafted
on the surface of ABEI-AuNPs by Au–S bond. Then, Cu2+ was captured onto the surface of ABEI-AuNPs by the coordination
reaction to form BF-AuNPs. The CL intensity of Cu2+-Cys/ABEI-AuNPs
was 1 order of magnitude higher than that of DTDTPA/Cu2+-ABEI-AuNPs synthesized by the previous work. Moreover, strong CL
emission of Cu2+-Cys/ABEI-AuNPs was also observed in neutral
pH conditions. In addition, the present BF-AuNPs synthesis method
exhibited advantages over the previous method in CL efficiency, simplicity,
and synthetic rate. Finally, by virtue of Cu2+-Cys/ABEI-AuNPs
as a platform, a simple CL chemosensor for the sensitive and selective
detection of pyrophosphate ion (PPi) was established based on the
competitive coordination interactions of Cu2+ between Cys
and PPi. The method exhibited a wide detection range from 10 nM to
100 μM, with a low detection limit of 3.6 nM. The chemosensor
was successfully applied to the detection of PPi in human plasma samples.
It is of great application potential in clinical analysis. This work
reveals that BF-AuNPs could be used as ideal nanointerface for the
development of novel analytical methods.