A fluorescence switch sensor for 6-mercaptopurine detection based on gold nanoparticles stabilized by biomacromolecule.

It is of great significance to develop a simple and powerful assay of 6-mercaptopurine (6-MP) because of its serious side effect and variable activity with the plasma concentration. In this contribution, a fluorescence switch sensor for trace amount detection of 6-MP was successfully developed based on the fluorescent gold nanoparticles stabilized by macromolecules. With the turn-off and on of the fluorescence signal at 640 nm of the analytical system, the selectivity of the present assay was largely improved. Trace amount of 6-MP could be detected in the linear range 1.0 x 10(-7) M-1.2 x 10(-4) M with a detection limit 1.98 x 10(-8) M. Under a UV lamp, the color change with the variation of the 6-MP concentration could be seen clearly by naked eyes. The sensitivity and selectivity are several-fold greater than other methods. And also it proved to be able to detect trace amount of 6-MP in real samples. The present assay largely improved the application of spectral methods in quantitative analysis of 6-MP. (C) 2012 Elsevier B.V. All rights reserved.