Rodrigues, Kelly B.
Fonseca, Fernando L. A.
Fernandes, Julio C. B.
Total Authors: 3
 Fac ABC Med 821, Dept Clin Med, Clin Lab, Principe Gales Ave, BR-09060650 Santo Andre, SP - Brazil
 Municipal Univ Sao Caetano do Sul 50, Santo Antonio St, BR-09521160 Sao Caetano do Sul, SP - Brazil
 Fed Univ Western Para UFOPA, Inst Educ Sci, S-N Marechal Rondon, BR-68040070 Santarem, PA - Brazil
Total Affiliations: 3
JOURNAL OF ANALYTICAL CHEMISTRY;
Web of Science Citations:
We developed an all-solid-state sensor for monoascorbate ion based on a composite containing copper(II) ions (5 wt %), graphite and epoxy resin. The sensor presented super-Nernstian response at room temperature under continuous bubbling of oxygen gas in sample. The detection limit of the sensor was 0.02 mM and its linear range was between 0.05 and 1.5 mM with upper limit of quantification equal to 3 mM. The leaching out effect of the active component from composite was estimated less than 11 mu g of copper(II) sulfate per day under continuous diffusion process in deionized water. Photomicrographs of the electrode surface did not show the presence of salt particles on the surface indicating that copper(II) ions could be intercalated in graphene layers. Attenuated total reflectance infrared spectrum demonstrated this possibility. The sensor was successfully applied to the in vitro determination of L-ascorbic acid in urine. (AU)