β-cyclodextrins-based inclusion complexes of CoFe2O4 magnetic nanoparticles as catalyst for the luminol chemiluminescence system and their applications in hydrogen peroxide detection

beta-cyclodextrins (beta-CD)-based inclusion complexes of CoFe2O4 magnetic nanoparticles (MNPs) were prepared and used as catalysts for chemiluminescence (CL) system using the luminol-hydrogen peroxide CL reaction as a model. The as-prepared inclusion complexes were characterized by XRD (X-ray diffraction). TGA (thermal gravimetric analysis) and FT-IR. The oxidation reaction between luminol and hydrogen peroxide in basic media initiated CL The effect of beta-CD-based inclusion complexes of CoFe2O4 magnetic nanoparticles and naked CoFe2O4 magnetic nanoparticles on the luminol-hydrogen peroxide CL system was investigated. It was found that inclusion complexes between beta-CD and CoFe2O4 magnetic nanoparticles could greatly enhance the CL of the luminol-hydrogen peroxide system. Investigation on the kinetic curves and the chemiluminescence spectra of the luminol-hydrogen peroxide system demonstrates that addition of CoFe2O4 MNPs or inclusion complexes between beta-CD and CoFe2O4 MNPs does not produce a new luminophor of the chemiluminescent reaction. The luminophor for the CL system was still the excited-state 3-aminophthalate anions (3-APA*). The enhanced CL signals were thus ascribed to the possible catalysis from CoFe2O4 MNPs or inclusion complexes between beta-CD and CoFe2O4 nanoparticles. The feasibility of employing the proposed system for hydrogen peroxide sensing was also investigated. Experimental results showed that the CL emission intensity was linear with hydrogen peroxide concentration in the range of 1.0 X 10(-7) to 4.0 x 10(-6) mol L-1 with a detection limit of 2.0 X 10(-8) MOl L-1 under optimized conditions. The proposed method has been used to determine hydrogen peroxide in water samples successfully. (C) 2010 Elsevier B.V. All rights reserved.