title: Determination of lapachol in the presence of other naphthoquinones using 3MPA-CdTe quantum dots fluorescent probe.
abstract: 3MPA-CdTe QDs in aqueous dispersion was used as a fluorescent probe for the determination of lapachol, a natural naphthoquinone found in plants of the Bignoniaceae family genus Tabebuia. Working QDs dispersions (4.5×10(-8) mol L(-1) of QDs) was prepared in aqueous media containing Tris-HCl buffer pH 7.4 and methanol (10% in volume). The excitation was made at 380 nm with signal measurement at 540 nm. To establish a relationship between fluorescence (corrected to inner filter effect) and concentration of lapachol, a Stern-Volmer model was used. The linear range obtained was from 1.0×10(-5) to 1.0×10(-4) mol L(-1). The limit of detection (x(b)-3s(b)) was 8.0×10(-6) mol L(-1). The 3MPA-CdTe QDs probe was tested in the determination of lapachol in urine, previously cleansed in an acrylic polymer. The average recovery was satisfactory.
authors.affiliation: Chemistry Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900 Rio de Janeiro, RJ, Brazil.
authors.forename: Ricardo Q
authors.initials: RQ
authors.lastname: Aucélio
authors.forename: Ana I
authors.initials: AI
authors.lastname: Peréz-Cordovés
authors.forename: Juliano L
authors.initials: JL
authors.lastname: Xavier Lima
authors.forename: Aurélio Baird B
authors.initials: AB
authors.lastname: Ferreira
authors.forename: Ana M
authors.initials: AM
authors.lastname: Esteva Guas
authors.forename: Andrea R
authors.initials: AR
authors.lastname: da Silva
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry*; D000042:Absorption; D019187:Cadmium Compounds / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D009285:Naphthoquinones / Q000032:analysis / Q000737:chemistry* / Q000652:urine; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence; D013691:Tellurium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D009285:Naphthoquinones; D015097:3-Mercaptopropionic Acid; C008252:lapachol; D013691:Tellurium; C028337:cadmium telluride