Peng D. L.,Ji H. F.,Dong X. D.,Tian J. F.,Wang M. H.,He L. H.,Zhang Z. Z.,Fang S. M.
In this study, a nanocomposite consisting of three-dimensional reduced graphene oxide (3D-rGO) and plasma-polymerized propargylamine (3D-rGO@PpPG) was prepared and used as a highly sensitive and selective DNA sensor for detecting Hg 2+ . Given the high density of amino groups in the resultant 3D-rGO@PpPG nanocomposite, thymine-rich and Hg 2+ -targeted DNA was preferentially immobilized on the fabricated sensor surface via the strong electrostatic interaction between DNA strands and the amino-functionalized nanocomposites, followed by detecting Hg 2+ through T–Hg 2+ –T coordination chemistry between DNA and Hg 2+ . The results of electrochemical measurements revealed that the anchored amount of DNA strands anchored on the 3D-rGO@PpPG nanofilm surface affects the determination of Hg 2+ in aqueous solution. It showed high sensitivity and selectivity toward Hg 2+ within concentrations ranging from 0.1 to 200 nM and displayed a low detection limit of 0.02 nM. The new strategy proposed also provides high selectivity of Hg 2+ against other interfering metal ions, good stability, and repeatability. The excellent applicability of the developed sensor confirms the potential use of plasma-modified nanofilms for the detection of heavy metal ions in real environmental samples and water.
Liu Liangbin,Tang Chongyang,Bu Lingzheng,Xiao Xiangheng,Huang Xiaoqing
Two-dimensional (2D) platinum (Pt)-based nanomaterials are considered as the ideal fuel cell catalysts, while their rational synthesis associated with phase control remains a formidable challenge. Herein, we firstly design the novel 2D Pt-lead-sulphur heterophased nanosheets (PtPbS HPNSs) as efficient high-toleration electrocatalysts for methanol oxidation reaction (MOR). They exhibit much higher activity and more highlighted bifunctional antipoisoning abilities than PtPb NSs and commercial Pt/C. Further density functional theory (DFT) simulation verifies that the decreased electron density of Pt sites worked by Pb and S makes CO intermediate favorable to desorb, avoiding the formation of CO*-polluted Pt sites. Simultaneously, this heterophased interface effectively weakens the adsorption of S 2− -species and improves the S-poisoning tolerance, showing a route to realize nearly innoxious catalysis. The present work highlights the importance of heterophase control in tuning antipoisoning property for 2D Pt-based nanomaterials, which is key for the rational design of efficient fuel cell anodic catalysts.
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