Synthesis, characterization and using a new terpyridine moiety-based ion-imprinted polymer nanoparticle: sub-nanomolar detection of Pb(II) in biological and water samples

A highly selective lead-imprinted polymer was synthesized via a thermal precipitation polymerization technique based on a terpyridine-based ligand as the complexing agent. The synthesized polymer was successfully incorporated in a graphite paste electrode (GPE) as the recognition element for lead ion (Pb2+). Differential pulse anodic stripping voltammetry (DPASV) technique was used to transduce the binding events at the modified electrode. The imprinted polymer nanoparticles (IP-NPs) were synthesized by precipitation polymerization of ethylene glycol dimethacrylate as the cross-linker, 2,2'-azobisisobutyronitrile as the free radical initiator and 2,2':6',6aEuro(3)-terpyridine (terpy) as the recognition element. The sensing procedure is based on the accumulation of lead ions at - 1.0 V vs. Ag/AgCl. Afterward, the DPV was recorded by the sweeping potential in a positive direction to oxidize the accumulated ions, leading to the appearance of a significant anodic peak. The constructed IIP-GPE revealed a linear response toward Pb2+ over the concentration range from 0.4 to 10 nM (with the sensitivity of 693.95 nA nM(-1) cm(-2)) and 10 nM to 1.0 A mu M (with the sensitivity of 580.25 A mu A A mu M-1 cm(-2)). The limit of detection (LOD) was evaluated to be 0.11 nM (for S/N = 3). The accuracy of the sensor was explored by analysis of a quality control material (QCMs, Seronorm (TM) urine REF NO 1011645) and different water samples. Selectivity studies showed no particular interference for detection of Pb(II).