Eu(III)-based polymeric nanoparticles as dual-emission turn-off sensor for anthrax biomarker detection

Anthrax is an acute infectious disease with high mortality caused by bacillus anthracis, which can severely harm human healthy. 2,6-pyridinedicarboxylic acid (DPA) is the main component and a major biomarker of bacillus anthracis. Therefore, it is essential to develop a sensitive and selective sensor for DPA detection. In this study, luminescent lanthanide nanoparticles, poly(PTEu)-PAA, were successfully synthesized by introducing Europium(III)-based complex and N-(4-(1,2,2-triphenylvinyl)phenyl)acrylamide (TPENA) to a hydrophilic macro-chain transfer agent poly(PEGMA)-PAA. The obtained poly(PTEu)-PAA nanoparticles were spherical with good dispersity, water stability and average diameters of approximately 443nm. Furthermore, poly(PTEu)-PAA nanoparticles can act as a dual emission ''turn-off'' probe for detecting DPA in water. Upon addition of DPA, the emission of Eu(TTA)2(AA)phen and TPENA centers in polymeric nanoparticles were quenched with the detection limits (LODs) of 0.30 μM (at 618nm) and 6.1μM (at 455nm), respectively, which was considerably lower than an infectious dosage of bacillus anthracis spores (60 μM) for a human being. Additionally, it showed high recoveries (92.50 %–102.45 %) in tap water, bovine serum, human serum and human urine samples. This is the first example of DPA sensor based on a dual-emission "turn-off" mechanism for Eu(III)-based polymeric nanoparticles, which presents a new avenue for detecting DPA.