title: Nanoparticle-based immunosensor with apoferritin templated metallic phosphate label for quantification of phosphorylated acetylcholinesterase.
abstract: A new sandwich-like electrochemical immunosensor has been developed for quantification of organophosphorylated acetylcholinesterase (OP-AChE), an exposure biomarker of organophosphate pesticides and nerve agents. Zirconia nanoparticles (ZrO2 NPs) were anchored on a screen printed electrode (SPE) to preferably capture OP-AChE adducts by metal chelation with phospho-moieties, which was selectively recognized by lead phosphate-apoferritin labeled anti-AChE antibody (LPA-anti-AChE). The sandwich-like immunoreactions were performed among ZrO2 NPs, OP-AChE and LPA-anti-AChE to form ZrO2/OP-AChE/LPA-anti-AChE complex and the released lead ions were detected on a disposable SPE. The binding affinity was investigated by both square wave voltammetry (SWV) and quartz crystal microbalance (QCM) measurements. The proposed immunosensor yielded a linear response current over a broad OP-AChE concentrations range from 0.05 nM to 10 nM, with detection limit of 0.02 nM, which has enough sensitivity for monitoring of low-dose exposure to OPs. This method avoids the drawback of unavailability of commercial OP-specific antibody as well as amplifies detection signal by using apoferritin encoded metallic phosphate nanoparticle tags. This nanoparticle-based immunosensor offers a new method for rapid, sensitive, selective and inexpensive quantification of phosphorylated adducts for monitoring of OP pesticides and nerve agents exposures.
authors.affiliation: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Du
authors.affiliation: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Aiqiong
authors.initials: A
authors.lastname: Chen
authors.affiliation: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Yunying
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors.forename: Aidong
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
authors.forename: Yuehe
authors.initials: Y
authors.lastname: Lin
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D001052:Apoferritins / Q000737:chemistry; D015374:Biosensing Techniques; D004563:Electrochemistry; D004781:Environmental Exposure; D007118:Immunoassay / Q000379:methods; D008670:Metals / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010575:Pesticides / Q000009:adverse effects; D010710:Phosphates / Q000737:chemistry; D010766:Phosphorylation
chemical_list: D008670:Metals; D010575:Pesticides; D010710:Phosphates; D001052:Apoferritins; D000110:Acetylcholinesterase