Polystyrene nanofibers capped with copper nanoparticles for selective extraction of glutathione prior to its determination by HPLC

Abstract

Polystyrene nanofibers were coated with copper nanoparticles (CuNPs) by a combination of electrospinning and in-situ reduction of Cu(II) using sodium borohydride as the reductant. The CuNPs on the nanofibers were characterized by energy dispersive spectrometry, scanning electron microscopy and transmission electron microscopy. A cartridge was packed with the nanofibers which then were activated with methanol and water. Glutathione (GSH) is found to quantitatively adsorbed by the packed cartridge at pH 3.0, and then can be desorbed with aqueous 2-mercaptoethanol and detected, after derivatization with ortho-phthalaldehyde, via high performance liquid chromatography with fluorometric detection. Under optimized conditions, the method has a 1.1 ng·mL detection limit and a response that is linear in the 10-1000 ng·mL GSH concentration range. The recoveries of GSH from artificial urine spiked at three levels (80, 400 and 800 ng·mL) are in the range of 94.6-98.6% with relative standard deviations (RSD) of <4.5% (n = 5). The method was applied to assessing the differences in urinary GSH between high-risk infants and healthy infants. The results show that the levels of GSH of normal infants are significantly higher than those of high-risk infants (P < 0.05). Graphical abstract Schematic of the preparation of CuNP-assembled nanofibers and the mechanism of extracting glutathione (GSH). GSH can be extracted by this material based on a strong interaction between the sorbent and GSH. This is attributed to the formation of Cu-S bonds between Cu and -SH.

Use of metal nanoparticles for preconcentration and analysis of biological thiols

“…Selection of the ligand influences the charge of the surface [9]. The thiol groups react under ambient conditions with certain NPs (i.e., AgNPs, AuNPs, and CuNPs) and displace the existing ligands on the surface and form a dative bond [10,11].…”

“…The position of LSPR is related to the particle size and the bandwidth is influenced by a polydispersity of the system, but as is mentioned previously, the position of LSPR is influenced by many factors; therefore, different effects should be considered in result evaluation. Scanning electron microscopy (SEM) is used for the evaluation of NP modifications, morphology, and size [11,22]. Other methods for NP characterization include dynamic light scattering (DLS) [23,24], X-ray diffraction, Fourier-transform infrared (FTIR) spectroscopy [25], or capillary electrophoresis (CE) [26].…”

Simultaneous Determination of Nine Quinolones in Pure Milk Using PFSPE-HPLC-MS/MS with PS-PAN Nanofibers as a Sorbent

“…To effectively implement the extraction, 4.0 mg of nanofibers was packed into the PFSPE column at the tip end of the storage cartridge [23]. Then, the column was activated using 200 μL of methanol and 200 μL of deionized water.…”

Target‐Activated DNA Polymerase Activity for Sensitive RNase H Activity Assay

“…[13,14] In particular, fluorometric methods have been extensively established due to their advantageous features of simplicity, reliability, and sensitivity. [15][16][17][18][19][20][21][22] The typical examples employing molecular beacons or G-quadruplexes rely on the fluorescence readouts resulting from RNase H-catalyzed reactions. [14,23,24] However, the signal response in these methods is not large enough for the sensitive determination of RNase H activity, which is attributed to the fact that a single target only promotes a single signaling event.…”