C1an15888k 400..405
نویسندگان
چکیده
As a sensitive and selective analytical technique, gold nanoparticles-based colorimetric sensing was characterized by its simplicity and cost-effectiveness. Specific methods have been extensively developed for different targets in diverse samples. In this study, a label-free method for sensing Co in aqueous solutions was described. The target was achieved by the induced aggregation of thiosulfate (S2O3 2 ) stabilized gold nanoparticles (AuNPs) in the presence of ethylenediamine (en). Co first reacted with en and formed complexes of Co(en)3 2+ in aqueous solutions, which was followed by the oxidation of Co(en)3 2+ to Co(en)3 3+ by dissolved oxygen. Co(en)3 3+ then attacked S2O3 2 ligands adsorbed on the AuNPs’ surfaces, forming positively charged (en)2CoS2O3 + on the AuNPs’ surfaces, which reduced the surface charges of AuNPs and induced the aggregation of AuNPs. The process was accompanied by a red-shift in the adsorption spectrum and a visible colour change from wine red to blue. Potential effects of relevant experimental conditions, including pH, concentrations of S2O3 2 and en, and incubation time were evaluated for optimization of the method. The proposed method is sensitive (LOD1⁄4 0.0 4 mM or 2.36 ppb) and selective (by at least 100-fold over other metal ions except for Cu) toward Co with a linear range from 0.1 to 0.7 mM. The cost-effective method allows rapid and simple determination of the concentrations of Co ions in drinking water.
منابع مشابه
Multilevel Analysis of Assessment Data
Introduction ......................................................................................................... 390 Data ...................................................................................................................... 391 PIRLS ................................................................................................................ 391 Plausible Value Outcome...
متن کاملQuestionnaire Administration Via the WWW: A Validation & Reliability Study for a User Satisfaction Questionnaire
Ben Harper Dept. of Laura Slaughter College Kent Norman Dept. of Psychology Lab for of Library and Psychology Lab for Automation Psychology Information Services Automation Psychology University of Maryland (CLIS) University of University of Maryland College Park, MD Tel: (301) Maryland College Park, College Park, MD Tel: (301) 405-5936 [email protected] MD Tel: (301) 405-5938 405-5924 kn8@uma...
متن کاملPhotoinactivation of Bacteria Attached to Glass and Acrylic Surfaces by 405 nm Light : 1 Potential Application for Biofilm
متن کامل
Fatty acid-modified microgels: transmission electron microscopy study
1 Department of Chemistry, University of Illinois at Urbana-Champaign. 600 South Mathews Avenue, Urbana, IL 61801, USA 2 Imaging Technology Group, The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign. 405 North Mathews Avenue, Urbana, IL 61801, USA 3 The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champ...
متن کاملCause of spectral variation in the luminescence of semisynthetic aequorins.
Aequorin emits light in the presence of Ca2+, decomposing into apoaequorin, coelenteramide and CO2. Semisynthetic aequorins, produced by replacing the coelenterazine moiety in aequorin with analogues of coelenterazine, showed widely different sensitivities to Ca2+ as well as certain spectral variations. A group of semisynthetic aequorins, e-type aequorins, showed bimodal luminescence, with peak...
متن کامل