Baseline separation of amino acid biomarkers of hepatocellular carcinoma by polyvinylpyrrolidone-filled capillary electrophoresis with light-emitting diode-induced fluorescence in the presence of mixed micelles

Abstract

Physiological amino acids (AAs) are important indices for monitoring various diseases, including cancer. This study proposes a polymer-based separation method in the presence of mixed micelles for the determination of AAs by capillary electrophoresis with light-emitting diode-induced fluorescence. The separation of 18 amino acid-cyano[f]benzoisoindoles (AA-CBIs) was successfully achieved using a solution of polyvinylpyrrolidone (PVP, 5% w/v, Mavg 1,300,000 Da). In addition, we demonstrated that mixed micelles composed of sodium dodecyl sulfate and isopropanol may affect the migration order of the AA-CBIs and greatly improve the speed of separation. With the exception of proline, 21 plasma AA-CBIs, including high isoelectric point AAs (lysine, ornithine, and arginine), were identified by using optimized separation conditions with minimal matrix effects. The results of this study demonstrated the distinct advantages of the proposed method, such as simplicity, high efficiency, and cost-effectiveness. This method has great potential for the diagnosis of several important diseases, including carcinomas, aminoacidopathies, and neurotransmission disorders.

Advances in the Determination of Nonprotein Amino Acids in Foods and Biological Samples by Capillary Electrophoresis

“…Fluorescence detection has also been widely employed for the analysis of NPAAs due to its high sensitivity; however, a derivatization procedure is also needed due to the lack of fluorescence of most amino acids. Many derivatization reagents such as 2,3-naphthalenedicarboxaldehyde (NDA) [9,10,11,12,13,14], 4fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) [15,16,17,18], fluorescein isothiocyanate (FITC) [19], 9-fluorenylmethyl chloroformate (FMOC-Cl) [20], benzoyl chloride, 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC), dansyl chloride (DNS-Cl) [21] and o-phthaldialdehyde (OPA) [16] have been employed. An interesting alternative to these detection approaches is mass spectrometry (MS) that presents higher sensitivity and selectivity than other systems [5] and provides structural information being not necessary a derivatization step although sometimes it is also employed.…”

Recent advances in amino acid analysis by capillary electromigration methods, 2013–2015

“…For example, liver's AA considered as cancer biomarkers are detected and separated by CE‐LEDIF. This detection is enhanced by the addition of PVP in the separation electrolyte . It is well accepted that D‐AA play an important physiological role.…”

Orthogonal Tip-to-Tip Nanocapillary Alignment Allows for Easy Detection of Fluorescent Emitters in Femtomolar Concentrations

“…We have created two EOF conditions in microcapillaries that have been entirely ( Figure S3a) or partially (Figure S3b−f) coated by polyvinylpyrrolidone (PVP) to suppress EOF. 42 Since tracking the single DNA molecules at this time scale is challenging using a low NA objective, we have measured the dynamics of fluorescently labeled beads (20 nm) inside the coated capillary ( Figure S3). The beads inside the completely coated capillary displayed a uniform velocity during electromigration ( Figure S3a, Movie S4).…”