Development of a novel luminol chemiluminescent method catalyzed by gold nanoparticles for determination of estrogens

Abstract

It has been found that gold nanoparticles (nano-Au) enhance the chemiluminescence (CL) of the luminol-hydrogen peroxide system and that estrogens inhibit these CL signals in alkaline solution. CL spectra, UV-visible spectra, X-ray photoelectron spectra (XPS), and transmission electron microscopy (TEM) were used to investigate the mechanism of the CL enhancement. On the basis of the inhibition, a flow-injection CL method has been established for determination of three natural estrogens. Under the optimized conditions, the linear range for determination of the estrogens was 0.07 to 7.0 micromol L(-1) for estrone, 0.04 to 10 micromol L(-1) for estradiol, and 0.1 to 10 micromol L(-1) for estriol. The detection limits were 3.2 nmol L(-1) for estrone, 7.7 nmol L(-1) for estradiol, and 49 nmol L(-1) for estriol, with RSD of 2.9, 2.6, and 1.8%, respectively. This method has been used for analysis of estrogens in commercial tablets and in urine samples from pregnant women.