Lanthanide Functionalized Metal-Organic Coordination Polymer: Toward Novel Turn-On Fluorescent Sensing of Amyloid β-Peptide.

Metal-organic coordination polymers (MOCPs) have been emerging as very attractive nanomaterials due to their tunable nature and diverse applications. Herein, using Tb as the luminescence center, 1,3,5-benzenetricarboxylate (BTC) as building block and Cu as the signal modulator as well as a recognition unit, we propose a novel and effective lanthanide functionalized MOCP (LMOCP) fluorescent sensor (Cu-BTC/Tb) for amyloid β-peptide (Aβ) monomer, a biomarker for Alzheimer disease (AD). Specifically, Cu-BTC/Tb, created by postsynthesis modification strategy under room temperature, is almost nonemissive due to the quenching effect of Cu in the MOCP, exhilaratingly, the presence of Aβ triggered a significant emission enhancement of Cu-BTC/Tb assay due to the high binding affinity of Aβ for Cu and the subsequent suppression of the quenching effect. In the assay, this LMOCP sensor shows high sensitivity with detection limit of 0.3 nM. Due to its capability to eliminate autofluorescence, Cu-BTC/Tb was also applied to the time-gated detection of Aβ in human plasma with promising results. This work presents a novel strategy for the construction of functional luminescent LMOCP for sensitively turn-on fluorescent sensing of Aβ. We believe the proposed strategy would inspire the development of various LMOCP-based fluorescent assays or medical imaging platforms for advanced biological implementations.