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

It is of great significance for superoxide anion (O) 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@Tb/guanosine 5'-monophosphate (GMP) NCPs with core-shell nanostructures was designed for O detection. The SiO@Tb/GMP NCPs core-shell nanostructures were produced by using SiO nanoparticles (NPs) as template to control their nano-size. First, Tb was adsorbed on the surface of SiONPs by coordination with -COOH of SiONPs. Then the Tb/GMP NCPs shells were grown along the surface of SiONPs. The SiO@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@Tb/GMP NCPs core-shell nanostructures displayed strong Tb/GMP emission which decreased linearly with the increased O concentration in the range from 5.3 nM to 6.0 μM with a limit detection of 2.18 nM. And the SiO@Tb/GMP NCPs core-shell nanostructures also exhibited good selectivity and high sensitivity in HEPES buffer at pH 7.4.