Nanoparticle‐filled capillary electrophoresis for the separation of long DNA molecules in the presence of hydrodynamic and electrokinetic forces

Abstract

We report the analysis of long DNA molecules by nanoparticle-filled capillary electrophoresis (NFCE) under the influences of hydrodynamic and electrokinetic forces. The gold nanoparticle (GNP)/polymer composites (GNPPs) prepared from GNPs and poly(ethylene oxide) were filled in a capillary to act as separation matrices for DNA separation. The separations of lambda-DNA (0.12-23.1 kbp) and high-molecular-weight DNA markers (8.27-48.5 kbp) by NFCE, under an electric field of -140 V/cm and a hydrodynamic flow velocity of 554 microm/s, were accomplished within 5 min. To further investigate the separation mechanism, the migration of lambda-DNA was monitored in real time using a charge-coupled device (CCD) imaging system. The GNPPs provide greater retardation than do conventional polymer media when they are encountered during the electrophoretic process. The presence of interactions between the GNPPs and the DNA molecules is further supported by the fluorescence quenching of prelabeled lambda-DNA, which occurs through an energy transfer mechanism. Based on the results presented in this study, we suggest that the electric field, hydrodynamic flow, and GNPP concentration are the three main determinants of DNA separation in NFCE.

Use of nanomaterials in capillary and microchip electrophoresis

“…Separation of naphthalene, biphenyl and thiourea [29] Baseline separation of dopamine and epinephrine [30] Neurotransmitters (dopamine and epinephrine) and environmental pollutants [31] Separation of thiourea, naphthalene, biphenyl and of the selected polycylic aromatic hydrocarbons [32] Immobilized dodecane thiol gold nanoparticles [33] Reversed-phase test mixture of three steroid drugs [34] Gold-based nanoparticles to manipulate selectivity [35] PEO solution containing gold nanoparticles to analysize DNA fragments in CZE [36,37,39] DNA separation in MCE using low-viscosity PEO (gold nanoparticle) solution [40,41] Silica nanoparticles…”

Analysis and applications of nanoparticles in capillary electrophoresis

“…This additional partitioning effect enables the separation not only of charged analytes but also of neutral species, provided that the NPs possess residual charges. Additionally, NPs are effective for the separation of hydrophobic compounds that are not easily resolved by a micellar pseudostationary phase in MEKC [24]. CGE is an adaptation of traditional gel electrophoresis for the analysis of proteins, DNA, and RNA.…”

“…The use of NPs as the pseudostationary phase was introduced by Wallingford and Ewing in 1989 [21]. Since then, many papers and reviews have reported the combination of MEKC and NPs [22][23][24]. The addition of NPs to the running buffer improves the separation by providing additional sites for the interaction with analytes.…”

Nanoparticle‐based pseudostationary phases in CEC: A breakthrough in protein analysis?

“…Since then, the major part of work has focused on analysis of low-molecular-weight compounds [15][16][17]. However, there are some examples of separation of high molecular weight compounds, such as DNA [18][19][20][21] and proteins [22][23][24][25][26][27][28]. Conventional DNA separations in CE based on physical polymer gels are limited by the high viscosity of the polymer solution, which makes replenishment cumbersome.…”