Luminescent SiO2@Tb/guanosine 5′-monophosphate core-shell nanoscale coordination polymers for superoxide anion detection

It is of great significance for superoxide anion (O-2(center dot-)) detection due to its important role in regulation of biological function. The nanoscale coordination polymers (NCPs) core -shell nanostructures have attracted increasing interests for their nanosized-dependent properties. In this study, SiO2@Tb/guanosine 5'-monophosphate (GMP) NCPs with core-shell nanostructures was designed for O-2(center dot-) detection. The SiO2@Tb/GMP NCPs core-shell nanostructures were produced by using SiO2 nanoparticles (NPs) as template to control their nano size. First, Tb3+ was adsorbed on the surface of SiO(2)NPs by coordination with -COOH of SiO(2)NPs. Then the Tb/GMP NCPs shells were grown along the surface of SiO(2)NPs. The SiO2@Tb/GMP NCPs core-shell nanostructures were characterized with scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Zeta potential. The resulted SiO2@Tb/GMP NCPs core-shell nanostructures displayed strong Tb/GMP emission which decreased linearly with the increased O-2(center dot-) concentration in the range from 5.3 nM to 6.0 sM with a limit detection of 2.18 nM. And the SiO2@Tb/GMP NCPs core-shell nanostructures also exhibited good selectivity and high sensitivity in HEPES buffer at pH 7.4.