Label-free, non-derivatization CRET detection platform for 6-mercaptopurine based on the distance-dependent optical properties of gold nanoparticles.

Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China. jxdu@snnu.edu.cn

Chemistry (Weinheim an der Bergstrasse, Germany) 2012 Jul 2

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A label-free, non-derivatization chemiluminescence resonance energy transfer (CRET) detection platform has been developed for the detection of the non-fluorescent small molecule 6-mercaptopurine. This CRET process arose from a chemiluminescent (CL) donor-acceptor system in which the reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO)-H(2)O(2)-fluorescein (maximum emission at 521.6 nm) served as the donor and gold nanoparticles (AuNPs, maximum absorption at 520.0 nm) served as the acceptor. This process caused a significant decrease in the CL signal of the TCPO-H(2)O(2)-fluorescein reaction. The presence of 6-mercaptopurine induced an aggregation of AuNPs with the assistance of Cu(2+) ions through cooperative metal-ligand interactions that was accompanied by a distinct change in color and optical properties. The maximum absorption band of the AuNPs was red-shifted to 721.0 nm and no longer overlapped with the CL spectrum of the reaction; as a result, the CL signal was restored. This CRET system exhibited a wide linear range, from 9.0 nmol L(-1) to 18.0 μmol L(-1), and a low detection limit (0.62 nmol L(-1)) for 6-mercaptopurine. The applicability of the proposed CRET system was evaluated by analysis of 6-mercaptopurine in spiked human plasma samples. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Citation

Jianxiu Du, Yadi Wang, Weimin Zhang. Label-free, non-derivatization CRET detection platform for 6-mercaptopurine based on the distance-dependent optical properties of gold nanoparticles. Chemistry (Weinheim an der Bergstrasse, Germany). 2012 Jul 2;18(27):8540-6