Luminescent nucleotide/Tb3+ coordination polymer for Fe(ii) detection in human serum

摘要

Metal-organic coordination polymers (CPs) have emerged as attractive functional nanomaterials because of their flexible composition and diverse architecture. Herein, we designed and synthesized a luminescent sensing nucleotide/Tb3+ CP, utilizing the self-assembly of adenosine triphosphate (ATP) as a biomolecule, Tb3+ as a luminescent ion, and 1,10-phenanthroline (Phen) as a cofactor ligand. The switched-on luminescence of ATP-Tb with Phen as a sensitizer was due to the removal of coordinating water molecules and the concomitant Phen-to-Tb3+ energy transfer. Employing Phen as a recognition unit with a high affinity to Fe2+, the configured ATP-Tb-Phen CP exhibited high sensitivity and selectivity to Fe2+. The decrease of luminescence intensity was linearly correlated with the Fe2+ concentration in the range of 20 nM to 1.5 mu M, with a detection limit of 20 nM. More importantly, a long luminescence lifetime of the ATP-Tb-Phen CP allowed time-resolved fluorimetric detection of Fe2+ ions in human serum, and can highly enhance its sensitivity by eliminating the background signal. Thus, our results indicate that metal-organic CPs are well suited for designing smart sensing materials, and feature unique advantages for the sensing of certain analytes.