Ratiometric fluorescence detection of ferric ion based on the nanohybrid of graphene quantum dots and semiconducting polymer nanoparticle
Date of Issue2016-05-25
School of Chemical and Biomedical Engineering
A ratiometric fluorescence sensor has been constructed through mixing amine graphene quantum dots (amine-GQDs) of green fluorescence PFO-DBT-F127 polymers of red fluorescence to detect ferric ions. The interaction between functional groups attached to the surface such as amine and carboxyl groups happens because of electrostatic attraction and hydrogen bonding. The ratiometric fluorescence sensor system exhibits double pronounced emission peaks at 540 and 680 nm under the excitation wavelength of 470 nm and can be used for sensitive detection of ferric ions. The ferric ions could absorbed onto the surface of amine-GQDs to induce a fluorescence quenching of the amine-GQDs based on the electron transfer (ET) mechanism. The addition of ferric ion leads to a significant fluorescence quenching for amine GQDs, but a negligible impact on that of semiconducting polymer nanoparticles (PFODBT-F127 NPs), thus resulting in a remarkable change of the fluorescence color from yellow to orange. This system is not only highly sensitive to Fe3+, but also exhibit remarkable selectivity towards Fe3+ over other metal ions including Cu2+, Ni2+, Co2+, Cd2+, Zn2+, Hg2+, Mg2+, Fe2+, K+ and Na+. More importantly, the changes of fluorescent colors of such probe can be applied for visual detection of ferric ions in real water.