Nanoscaled lanthanide/nucleotide coordination polymer for detection of an anthrax biomarker

The metal-organic coordination polymers as attractive functional nanomaterials have shown a promising potential in a variety of important applications. In this work, we employed a hydrophilic lanthanide/nucleotide coordination polymer constructed by spontaneous self-assembling of terbium ion (Tb3+) and adenosine monophosphate (AMP) as a receptor platform for direct detection of anthrax biomarker (dipicolinic acid, DPA) in aqueous solution. Due to the coordination of DPA with Tb3+ on the surface of the AMP/Tb, significant enhancement in the fluorescent intensity of the coordination polymer (AMP/Tb) was obtained. The enhanced fluorescence intensity of AMP/Tb displayed a good linear response to DPA concentrations in the range from 20 nM to 20 μM with a detection limit of 10 nM. As a kind of DPA sensor, the AMP/Tb also showed excellent selectivity. Compared with conventional receptor platforms based on molecular lanthanide compounds, the presented receptor platform has an advantage of allowing simple, direct analysis for DPA without requiring complicated preparation processes and any extra steps of surface modification. This presented straightforward strategy may be extended to the construction of other coordination polymer-based lanthanide receptor reagent and hence a wider application field of coordination polymer as fluorescent sensor is expected.