RESUMO
We have demonstrated for the first time the suitability of fluorosurfactant-capped spherical gold nanoparticles as HPLC postcolumn colorimetric reagents for the direct assay of cysteine, homocysteine, cystine, and homocystine. The success of this work was based on the use of an on-line tris(2-carboxyethyl)phosphine reduction column for cystine and homocystine. Several parameters affecting the separation efficiency and the postcolumn colorimetric detection were thoroughly investigated. Under the optimized conditions, cysteine, homocysteine, cystine, and homocystine in human urine and plasma samples were determined. Detection limits for cysteine, homocysteine, cystine, and homocystine ranged from 0.16-0.49 µM. The accuracy in terms of recoveries ranged between 94.0-102.1%. This proposed method was rapid, inexpensive, and simple.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cisteína/análise , Cistina/análise , Homocisteína/análise , Homocistina/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Cisteína/sangue , Cisteína/urina , Cistina/sangue , Ouro/química , Homocisteína/sangue , Homocisteína/urina , Homocistina/sangue , Homocistina/urina , Humanos , Nanopartículas/químicaRESUMO
We report a novel approach for preparation of networked gold nanoparticles (AuNPs) using reactive oxygen species (i.e., peroxymonocarbonate, HCO(4)(-)) as a novel reducing agent, along with nonionic fluorosurfactant (FSN) assistance. The formation mechanism of the networked AuNPs is demonstrated by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV-visible spectroscopy, powder X-ray diffraction (XRD) measurement and energy dispersive X-ray spectroscopy (EDS). In this case, HCO(4)(-) serves as a reducing agent for the preparation of the networked AuNPs, and further as a strong oxidizing agent attached to the surface of networked AuNPs, which can trigger the strong CL emission from luminol without the addition of H(2)O(2). In addition, FSN can control and stabilize the crystal morphology of the networked AuNPs, and improve the selectivity of the CL detection system for aminothiols. Finally, the networked AuNPs have been applied for ultrasensitive detection of aminothiols in human urine and plasma samples.