title: Molecularly imprinted polypyrrole nanonecklaces for detection of herbicide through molecular recognition-amplifying current response.
abstract: Molecularly imprinted polypyrrole (PPy) nanonecklaces were facilely synthesized through a two-step oxidative polymerization route for the amperometric detection of non-electrochemically active herbicide. It has been demonstrated that dissolved oxygen can preoxidize pyrrole to form PPy oligomer bundles, which further self-assemble into necklace-like micelles in the presence of cetyltrimethylammonium bromide. Subsequently, these microstructures were immediately gelled through quick polymerization of residual pyrrole monomers, leading to the formation of PPy nanonecklaces. Meanwhile, herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was synchronously imprinted into the formed PPy and highly dense imprinted sites were generated in PPy nanonecklaces because the necklace-like structure with microgaps/pores provides the facile and complete removal of templates. The imprinted nanonecklaces exhibit the high capacity and fast kinetics to uptake 2,4-D molecules, and produce a imprinting factor of ~4.2. Importantly, the recognition and binding to 2,4-D significantly amplify the current response by a factor of 8 times in amperometric measurements, providing a sensitive detection of 2,4-D. The molecular imprinting strategy opens a novel avenue to the direct detection of non-electrochemically active species in a more convenient, simpler and cheaper way than the traditional competition-displacing approaches.
authors.affiliation: Institute of Intelligent Machines, Chinese Academy of Sciences, Peninsula near Shushan Lake, Hefei, Anhui, 230031, China.
authors.forename: Guijian
authors.initials: G
authors.lastname: Guan
authors.forename: Shuangshuang
authors.initials: S
authors.lastname: Wang
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhou
authors.forename: Kui
authors.initials: K
authors.lastname: Zhang
authors.forename: Renyong
authors.initials: R
authors.lastname: Liu
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Mei
authors.forename: Suhua
authors.initials: S
authors.lastname: Wang
authors.forename: Zhongping
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D006540:Herbicides / Q000032:analysis*; D006801:Humans; D054802:Molecular Imprinting / Q000295:instrumentation / Q000379:methods*; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry; D011108:Polymers / Q000032:analysis*; D011758:Pyrroles / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D002593:Cetrimonium Compounds; D006540:Herbicides; D011108:Polymers; D011758:Pyrroles; D015084:2,4-Dichlorophenoxyacetic Acid; C067635:polypyrrole; D000077286:Cetrimonium