• Inicio
  • Resultados de la búsqueda
  • Gold nanoparticle extraction followed by o-phthaldialdehyde derivatization for fluorescence sensing of different forms of homocysteine in plasma.

Gold nanoparticle extraction followed by o-phthaldialdehyde derivatization for fluorescence sensing of different forms of homocysteine in plasma.

Talanta (2012-03-01)
Yi-Jhen Lai, Wei-Lung Tseng
RESUMEN

This study reports a selective and sensitive method for fluorescent detection of total, protein-bound, free, and free oxidized homocysteine (HCys) using tris(2-carboxyethyl)phosphine (TCEP) as a reducing agent, fluorosurfactant-capped gold nanoparticles (FSN-AuNP) as a preconcentrating probe, and o-phthaldialdehyde (OPA) as a derivatizing agent. TCEP was used to reduce the disulfide bonds of protein-bound and free oxidized HCys. FSN-AuNPs can extract HCys from a complicated complex because the FSN capping layer stabilizes the AuNPs in a high-salt solution and inhibits non-specific adsorption. HCys was selectively derivatized with OPA in the absence of a nucleophile. By taking advantage of these features, the selectivity of the proposed system is greater than 100-fold for HCys and homocystine (HCys-HCys disulfide; diHCys) compared to any aminothiols. The limits of detection for HCys and diHCys were 4.4 and 4.6 nM, respectively. Different forms of plasma HCys were determined by varying the order of disulfide reduction with TCEP.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Phthaldialdehyde, ≥97% (HPLC), powder (may contain lumps)
Sigma-Aldrich
Phthaldialdehyde Reagent, Solution Complete
Sigma-Aldrich
Phthaldialdehyde, suitable for HPLC fluorimetric detection of amino acids, ≥99% (HPLC), powder
Sigma-Aldrich
Phthaldialdehyde, for fluorescence, ≥99.0% (HPLC)
Sigma-Aldrich
Phthaldialdehyde Reagent, Solution Incomplete