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

It is of great significance for superoxide anion (O₂^•-) 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 O₂^•- 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 SiO₂NPs by coordination with -COOH of SiO₂NPs. Then the Tb/GMP NCPs shells were grown along the surface of SiO₂NPs. 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 O₂^•- concentration in the range from 5.3 nM to 6.0 μM 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.