초록 |
In the present work, we have prepared a phthalazine derivative 13-(4-bromophenyl)-3,3-dimethyl-3,4-dihydro-1H-indazolo [1,2-b] phthalazine-1,6,11(2H,13H)-trione based fluorescent organic nanoparticles IDP NPs in an aqueous medium by a simple reprecipitation method. The IDP NPs exhibited turn-off type fluorescence with high selectivity and sensitivity for simultaneous recognition of Cr6+ and Mn7+ among other biologically important cations and anions with good anti-interference capability. Under the selected optimized conditions, the fluorescent intensity of IDP NPs studied at an excitation wavelength of λex = 360 nm, quenched gradually by the continuous addition of concentrations of Cr6+ and Mn7+ ions. Similarly, selective fluorescence quenching for IDP NPs with the addition of Cr6+ and Mn7+ ion was discussed on the inner filter effect and non-radiative photoinduced oxidative electron transfer process respectively and it was supported by absorption, fluorescence spectral, Zeta-sizer and fluorescence lifetime measurements. In addition, the fluorescent quenching experimental data were found to fit the Stern–Volmer relationship in the concentration range of 0–50 μg.mL-1 and 0–80 μg.mL-1 with a limit of detection (LOD) 3.715 µg.mL-1 and 4.059 µg.mL-1 towards Cr6+ and Mn7+ respectively. Moreover, IDP NPs have been successfully used for the quantitative determination of Cr6+ and Mn7+ in different environmental water samples. |