Highly sensitive and selective hyphenated technique (molecularly imprinted polymer solid-phase microextraction-molecularly imprinted polymer sensor) for ultra trace analysis of aspartic acid enantiomers.
J Chromatogr A
; 1283: 9-19, 2013 Mar 29.
Article
em En
| MEDLINE
| ID: mdl-23415444
ABSTRACT
The present work is related to combination of molecularly imprinted solid-phase microextraction and complementary molecularly imprinted polymer-sensor. The molecularly imprinted polymer grafted on titanium dioxide modified silica fiber was used for microextraction, while the same polymer immobilized on multiwalled carbon nanotubes/titanium dioxide modified pencil graphite electrode served as a detection tool. In both cases, the surface initiated polymerization was found to be advantageous to obtain a nanometer thin imprinted film. The modified silica fiber exhibited high adsorption capacity and enantioselective diffusion of aspartic acid isomers into respective molecular cavities. This combination enabled double preconcentrations of d- and l-aspartic acid that helped sensing both isomers in real samples, without any cross-selectivity and matrix complications. Taking into account 6×10(4)-fold dilution of serum and 2×10(3)-fold dilution of cerebrospinal fluid required by the proposed method, the limit of detection for l-aspartic acid is 0.031ngmL(-1). Also, taking into account 50-fold dilution required by the proposed method, the limit of detection for d-aspartic acid is 0.031ngmL(-1) in cerebrospinal fluid.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ácido Aspártico
/
Microextração em Fase Sólida
/
Impressão Molecular
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article