Abstract
We have reported the preparation and characterization of a novel, freestanding, paper-like graphene (G)-poly(diallyldimethylammoniumchloride) (PDDA)-Fe3O4 nanoparticles (NPs) composite. This G-based flexible buckypaper (BP) composed of stacked G-PDDA-NP platelets exhibited excellent mechanical properties, superior electrical properties, and enzyme mimetic activity, making it potentially suitable for in electrochemical sensor applications. The negatively charged NPs were immobilized on positively charged G-PDDA through the electrostatic interaction to form nanoscale G-PDDA-NP platelets, which were further assembled by flow-directed assembly to form BP. The resulting BP has macroscopic flexibility and stiffness due to the van der Waals forces between nanoscale G-PDDA-NP platelets and interlocking-tile arrangement of the platelets. The morphology and structure of the individual G-PDDA-NP platelets and the resulting BP were analyzed by using AFM, SEM and EDX. The BP was attached to an Au or Pt electrode to construct a nonenzyme H2O2 chemical sensor. The NPs acted as a "spacer" to increase the distance between the G sheets and decrease the chances of formation of a stacked graphitic structure, thereby increasing the surface area of the G electrode. The Fe3O4 NPs immobilized and embedded in the BP have intrinsic enzyme mimetic activity like natural peroxidase. The high surface area and excellent electrical conductivity of G improved the catalytic properties of NPs. The obtained H2O 2 chemical sensor exhibited prominent electrocatalytic activity towards H2O2, with a wide linear range from 10 ppm (∼0.3 μM) to 800 ppm (∼23 mM), correlation coefficient of 0.986, and a high sensitivity of 218 μA mM-1 ·cm-2. Such low-cost G-PDDA-NP composite BPs prepared by facile methods pave way towards novel sensors with better performance.
Original language | English |
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Pages (from-to) | 7349-7357 |
Number of pages | 9 |
Journal | Journal of Nanoscience and Nanotechnology |
Volume | 13 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2013 Nov |
Keywords
- Enzyme-free electrochemical HO sensor
- Graphene buckypaper
- Graphene-PDDA-iron oxide NP composite
- Large detection range
ASJC Scopus subject areas
- Bioengineering
- General Chemistry
- Biomedical Engineering
- General Materials Science
- Condensed Matter Physics