Publication details
Capillary electrophoresis with laser induced fluorescence for the analysis of biological thiols in exhaled breath condensate after preconcentration using gold and gold-grafted magnetic nanoparticles
| Authors | |
|---|---|
| Year of publication | 2026 |
| Type | Article in Periodical |
| Magazine / Source | TALANTA |
| MU Faculty or unit | |
| Citation | |
| web | https://doi.org/10.1016/j.talanta.2025.128550 |
| Doi | https://doi.org/10.1016/j.talanta.2025.128550 |
| Keywords | Biothiols; Gold nanoparticles; Magnetic-gold nanoparticles; Preconcentration; Capillary electrophoresis; Laser induced fluorescence; Exhaled breath condensate |
| Description | Gold and Fe3O4-Au composite magnetic nanoparticles were employed for the selective extraction and preconcentration of cysteine, homocysteine, and glutathione from exhaled breath condensate (EBC) samples. Using a cascade type EBC sampler, 1 mL of EBC was collected, and biological thiols were extracted and preconcentrated with preconcentration factors ranging from 8 to 34. The extraction process involved binding thiols to nanoparticles, separating them from the sample matrix, and then releasing them from the nanoparticles using dithiothreitol (DTT). The preconcentrated thiols were subsequently derivatized with naphthalene-2,3dicarboxaldehyde. This derivatization method allowed for the use of high DTT concentrations without interfering with the separation step due to the presence of the -SH group. The separation was performed in a 10 mM sodium borate buffer at pH 10. A cost-effective 405 nm laser-induced fluorescence detector was constructed and utilized for detection. The method was linear between 0 and 50 nM, with R2 in the range of 0.9948-0.9998 and LODs of 0.24 nM, 0.63 nM and 0.71 nM were achieved for cysteine, homocysteine and glutathione, respectively. The precision expressed as RSD of peak areas was between 6.8 and 8.7 %. The average relative spike recoveries for cysteine, homocysteine and glutathione in EBC samples were 76 %, 84 %, and 80 %, respectively, with a range of 54 %-112 % across three different concentration levels. Additionally, Fe3O4-Au magnetic nanoparticles were tested and enabled rapid magnetic separation, reducing processing time and highlighting the potential for automation. This optimized preconcentration procedure demonstrated efficient biothiol extraction with very low detection limits, enabling, for the first time, the simultaneous analysis of these three thiols in EBC. |