Abstract
A thin composite film of carbon nanoparticles (ca. 8 nm diameter) and chitosan biopolymer (poly-D-glucosamine, from chitin, 75-85% deacetylated) was prepared by evaporation from aqueous dispersion onto glassy carbon electrode surfaces. The amine groups in the chitosan biopolymer were used to effectively bind Hg(II) ions from an aqueous pH 5 KCl solution. During redox cycling voltammetric responses for bound mercury are readily observed and mercury nanodroplets (ca. 5.4 (± 1.0) nm diameter based on SAXS measurements) are formed in the film by applying a negative potential. The binding of Hg(II) ions to the chitosan-carbon nanoparticle film occurs with an approximate Langmuirian constant of 2.7 × 104 mol-1dm3 and the process is dependent on (i) the chitosan content in the film, (ii) the Hg 2+ concentration, and (iii) the immobilization time. The immobilized mercury nanodroplets within the carbon nanoparticle - chitosan film are electrochemically active and allow the co-deposition of other metals in the form of amalgams. Preliminary experiments for the anodic stripping voltammetry for Pb2+ and for Cu2+ are demonstrated. Mercury nanodroplet modified chitosan - carbon nanoparticle film electrodes represent a novel electroanalytical tool.
Original language | English |
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Pages (from-to) | 261-266 |
Number of pages | 6 |
Journal | Electroanalysis |
Volume | 21 |
Issue number | 3-5 |
DOIs | |
Publication status | Published - Feb 2009 |
Externally published | Yes |
Keywords
- Carbon nanoparticles
- Chitosan
- Mercury
- Nanodroplet
- Sensor
- Voltammetry
ASJC Scopus subject areas
- Analytical Chemistry
- Electrochemistry