Luminescent and magnetic Fe 3O 4/Py/PAM nanocomposites for the chromium(VI) determination

Abstract

A novel luminescent and magnetic Fe 3O 4/pyrene/polyacrylamide (Fe 3O 4/Py/PAM) nanocomposite has been prepared under ultrasonic radiation. This magnetic nanocomposite combined with pyrene would lead to a special functional magnetic luminescent composite that enjoys both the advantages of magnetic nanoparticles of Fe 3O 4 and fluorescence nanoparticles of pyrene. Taking advantage of the magnetic property of Fe 3O 4 nanocomposites, we can separate Fe 3O 4/Py/PAM nanocomposites from solution easily just by using a permanent magnet. Based on the fluorescence quenching of Fe 3O 4/Py/PAM nanocomposites by Cr(VI), a method for the selective determination of Cr(VI), without separation of Cr(III) in water, was developed. Under optimal experimental conditions, a limit of detection of 0.01 μg mL −1 was achieved. The calibration curve was linear over the concentration range of 0.1–14.0 μg mL −1 with a correlation coefficient of 0.9975. The proposed method has been applied to the selective quantification of Cr(VI) in synthetic samples and wastewater samples with the satisfactory results.