title: Development of a voltammetric sensor for diospyrin determination in nanomolar concentrations.
abstract: A sensor based on glassy carbon (GC) electrode modified with cobalt tetrasulfonated phthalocyanine (CoTSPc) and a poly-l-lysine (PLL) film is proposed for diospyrin determination in nanomolar concentrations with differential pulse voltammetry (DPV) technique. The modified electrode showed excellent catalytic activity presenting much higher peak currents than those measured on a bare GC electrode. Linear response range, sensitivity and limit of detection (LOD) were of 1-120nmoll(-1), 220.46nAlnmol(-1)cm(-2) and 0.3nmoll(-1), respectively. The repeatability of the proposed sensor, evaluated in term of relative standard deviation (R.S.D.), was measured as 4.4% for 10 experiments in 50mumoll(-1) diospyrin samples. The developed sensor was applied for the determination of diospyrin in the crude extracts of the stem-bark of Diospyros montana Roxb. and the average recovery for these samples was 101.9 (+/-3.1)%.
authors.affiliation: Department of Chemistry, CCEN, Federal University of Alagoas, 57072-970 Maceió, AL, Brazil.
authors.forename: Cicero
authors.initials: C
authors.lastname: de Oliveira Costa
authors.forename: Paulo R B
authors.initials: PR
authors.lastname: Miranda
authors.forename: Banasri
authors.initials: B
authors.lastname: Hazra
authors.forename: Madhushree
authors.initials: M
authors.lastname: Das Sarma
authors.forename: Rita
authors.initials: R
authors.lastname: de Cássia Silva Luz
authors.forename: Lauro Tatsuo
authors.initials: LT
authors.lastname: Kubota
authors.forename: Marília Oliveira Fonseca
authors.initials: MO
authors.lastname: Goulart