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 •− ) 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, SiO 2 @Tb/guanosine 5′-monophosphate (GMP) NCPs with core-shell nanostructures was designed for O 2 •− detection. The SiO 2 @Tb/GMP NCPs core-shell nanostructures were produced by using SiO 2 nanoparticles (NPs) as template to control their nano-size. First, Tb 3+ 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 SiO 2 @Tb/GMP NCPs core-shell nanostructures were characterized with scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Zeta potential. The resulted SiO 2 @Tb/GMP NCPs core-shell nanostructures displayed strong Tb/GMP emission which decreased linearly with the increased O 2 •− concentration in the range from 5.3 nM to 6.0 μM with a limit detection of 2.18 nM. And the SiO 2 @Tb/GMP NCPs core-shell nanostructures also exhibited good selectivity and high sensitivity in HEPES buffer at pH 7.4.