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Metal organic coordination polymers have emerged as a new class of functional nanomaterials because of their flexible components and diverse architecture. Here, we report the synthesis of a luminescent sensing nucleotide/Tb3+ coordination polymer by the self-assembly of a biomolecule nucleotide, a lanthanide ion and a functional ligand 1,10-phenanthroline. Due to the incorporation of 1,10-phenanthroline as both a sensitizer and a recognition unit, the luminescence of this coordination polymer was enhanced 32 times, and exhibited excellent selectivity and sensitivity to the iron(II) ions. This coordination polymer containing Tb3+ ions has a long luminescence lifetime of up to a millisecond, and was applied to detect Fe2+ ions in human serum by time-resolved fluorimetry. The detection limit is as low as 30 nM. The results demonstrate that metal organic coordination polymers have great potential in constructing specific nanosensors through their components and structural flexibility, and could provide new chemical sensing methods for ions/molecules. [ABSTRACT FROM AUTHOR]

Background: Water-dispersed lanthanide coordination polymers (LCPs) have attracted considerable attention owing to their superiority in bioanalysis. However, so far, most of the reported LCPs, due to the employment of water-insoluble and toxic organic molecules as ligands, are only competent in organic solution or the gaseous phase. Therefore, the construction of a water-dispersed, LCP-based, especially LCP nanoparticle (LCPNP)-based, sensor is still lacking and challenging., Objective: The aim was to obtain a novel and effective LCPNP-based sensor for Zn2+ by simple self-assembly, utilizing water-soluble guanosine monophosphate (GMP) as ligand and Eu3+ as luminescence center, ., Methods: In aqueous solutions, Eu-GMP NPs were formed via self-assembly reaction between Eu3+ and GMP, and displayed very weak fluorescence due to low energy transfer from GMP to Eu3+ and the rate constant of nonradiactive deactivation of the excited states caused by the O-H vibration of coordinated water molecules. After the introduce of Zn2+, forming Eu-GMP/Zn, very interestingly, an 8-fold fluorescence enhancement was observed due to the removal of coordination water molecules and fluorescence sensitization of Zn2+., Results: The fluorescence intensity of Eu-GMP NPs at 614 nm showed a linear relationship with the concentration of Zn2+ from 4 to 240 μM with a detection limit of 4 μM. Due to possessing long fluorescence, Eu-GMP showed prominent achievment for application in serum Zn2+ determination., Conclusion: The LCPNP probe exhibited excellent performance for the determination of Zn2+ in serum., Highlights: For the first time, we developed and designed a kind of water-dispersed, LCPNP-based turn-on fluorescence assay for Zn2+ in serum. High sensitivity and good recoveries were achieved due to long fluorescence life, good water-dispersed behavior, and the turn-on fluorescence response of the LCPNP probe., (© The Author(s) 2022. Published by Oxford University Press on behalf of AOAC INTERNATIONAL. All rights reserved. For permissions, please email: journals.permissions@oup.com.)