Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2010–2012)

Breadmore, Michael C.; Grochocki, Wojciech; Kalsoom, Umme; Alves, Mónica N.; Phung, Sui Ching; Rokh, Masoomeh Tehrani; Cabot, Joan M.; Ghiasvand, Alireza; Li, Feng; Shallan, Aliaa I.; Keyon, Aemi Syazwani Abdul; Alhusban, Ala A.; See, Hong Heng; Wuethrich, Alain; Dawod, Mohamed; Quirino, Joselito P.

doi:10.1002/elps.201200396

Cited by 163 publications

(84 citation statements)

References 242 publications

(283 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This can be overcome by the application of stacking techniques such as online preconcentration step which have been summarized in recent general reviews on the topic [14][15][16][17]. For example, sweeping was employed to achieve the appropriate sensitivity when monitoring the activity of nucleotide pyrophosphatases/phosphodiesterases [18] as well as for a MEKC assay of sirtuin enzymes [19].…”

Section: Pre-capillary Enzyme Assaysmentioning

confidence: 99%

Advances in Capillary Electrophoresis-Based Enzyme Assays

Scriba

Belal

2015

Chromatographia

View full text Add to dashboard Cite

IntroductionEnzymes catalyze metabolic reactions in cells regulating homeostasis, growth and reproduction of living organisms. Enzymes are also often involved in human disease. The analysis of the human genome has revealed that within the so-called druggable genome a significant portion (in some analyses more than half) of the potential drug targets are enzymes [1][2][3]. Consequently, enzymes are important targets in the development of new drugs. Moreover, enzymes play a role in the clinical diagnosis of diseases. Therefore, effective methods for characterization of enzymes as well as for the determination of their activity are important, for example, for the understanding of enzyme-mediated metabolic reactions or the identification of substrates and inhibitors for the treatment of human diseases.Capillary electrophoresis (CE) has been applied to enzyme analysis for more than 20 years since the first report by Banke et al. on an assay of alkaline protease [4]. Since then, all aspects of enzyme-related analysis have been studied by CE methods including the evaluation of enzymatic activity, enzyme kinetics, identification and characterization of enzyme inhibitors and activators as well as metabolic pathways as, for example, summarized in [5][6][7][8][9][10][11][12].Generally, CE-based enzyme assays can be divided in three groups, pre-capillary (offline) assays, in-capillary (online) assays and post-capillary assays. In the pre-capillary assays, all required components including enzyme, substrate, co-factors, etc., are mixed in a vial and incubated for an intended period of time. Subsequently, the reaction is quenched and an aliquot is subjected to CE analysis for the determination of substrate(s) and/or co-substrate(s) and/ or product(s). Multiple sampling or repeated sampling in combination with sequential runs for the determination of Abstract Capillary electrophoresis (CE) has become a flexible and accurate, high-efficiency analytical separation technique in many areas requiring only minute amounts of sample and chemicals. Thus, CE has also been recognized as a suitable technique to study enzymatic reactions including the determination of Michaelis-Menten kinetic data or the identification and characterization of inhibitors. The most often applied CE-based enzyme assay modes can be divided into two categories: (1) pre-capillary assays where incubations are performed offline followed by CE analysis of substrate(s) and/or product(s) and (2) in-capillary assays in which the enzymatic reaction and analyte separation are performed in the same capillary. In case of the in-capillary assays, the enzyme may be immobilized or in solution. The latter is also referred to as electrophoretically mediated microanalysis (EMMA), while in the case of immobilized enzyme the term immobilized enzyme reactor (IMER) is used. The present review summarizes the literature on CEbased enzyme assays published between January 2010 and April 2015. Immobilized enzyme reactors as well as microfluidic devices applied to the study of enzymatic a...

show abstract

Section: Pre-capillary Enzyme Assaysmentioning

confidence: 99%

Advances in Capillary Electrophoresis-Based Enzyme Assays

Scriba

Belal

2015

Chromatographia

View full text Add to dashboard Cite

show abstract

“…When the sample was introduced with pressure, it is called field amplified sample stacking (FASS). When the sample was introduced electrokinetically, it is called field amplified sample injection (FASI) [32]. MSS relies on the transport of the micelle bound charged analyte and the reversal of the analytes' effective electrophoretic mobility at the MSS boundary between the micellar zone and the adjacent zone [7].…”

Section: Micelle To Solvent Stacking Via Sample Injection Under Fieldmentioning

confidence: 99%

Application of Capillary Electrophoretic On-Line Sequential Concentration Based on Micelle to Solvent Stacking

Sun¹,

Lu²,

Yuan³

et al. 2018

AJAC

View full text Add to dashboard Cite

To take advantage of micelle to solvent stacking (MSS) to achieve more sensitivity enhancement with enough selectivity, the application of capillary electrophoretic on-line sequential concentration based on the MSS was reviewed. MSS has been coupled to sweeping FASS, FASI and normal EKI. Furthermore, multiple stacking by coupling MSS with more than one stacking method has also been reported. It is more sensitive and selective than solely used of one or two stacking methods and is very suitable for complex and trace sample analysis.

show abstract

“…This boundary can be created by changes in conductivity (as in field-amplified sample stacking and isotachophoresis), or changes in pH (as in dynamic pH junction), or inclusion of a pseudostationary phase (as in sweeping and micelle collapse) [22][23][24][25]. A series of biannual reviews, first published in Electrophoresis in 2007 [26] and continued in 2009 [27], 2011 [28], 2013 [29], and 2015 [30] To the best of our knowledge, some reviews and book chapters on IL-based surfactants cover the use of ILs in CE [32,33], but in the present work, for the first time, we described the applications resulted from implementing ILs in enhancing the sensitivity of CE. Figure 2 shows a chart summarizing the different modes based on ILs in enhancing the sensitivity of CE.…”

Section: Introductionmentioning

confidence: 99%

Ionic liquids in enhancing the sensitivity of capillary electrophoresis: Off‐line and on‐line sample preconcentration techniques

2016

View full text Add to dashboard Cite

The popularity of ionic liquids (ILs) has grown during the last decade in enhancing the sensitivity of CE through different off-line or on-line sample preconcentration techniques. Water-insoluble ILs were commonly used in IL-based liquid phase microextraction, in all its variants, as off-line sample preconcentration techniques combined with CE. Water-soluble ILs were rarely used in IL-based aqueous two phase system (IL-ATPS) as an off-line sample preconcentration approach combined with CE in spite of IL-ATPS predicted features such as more compatibility with CE sample injection due to its relatively low viscosity and more compatibility with CE running buffers avoid, in some cases, anion exchange precipitation. Therefore, the attentions for the key parameters affecting the performance of IL-ATPSs were generally presented and discussed. On-line CE preconcentration techniques containing IL-based surfactants at nonmicellar or micellar concentrations have become another interesting area to improve CE sensitivity and it is likely to remain a focus of the field in the endeavor because of their numerous to create rapid, simple and sensitive systems. In this article, significant contributions of ILs in enhancing the sensitivity of CE are described, and a specific overview of the relevant examples of their applications is also given.

show abstract

Recent advances in enhancing the sensitivity of electrophoresis and electrochromatography in capillaries and microchips (2010–2012)

Cited by 163 publications

References 242 publications

Advances in Capillary Electrophoresis-Based Enzyme Assays

Advances in Capillary Electrophoresis-Based Enzyme Assays

Application of Capillary Electrophoretic On-Line Sequential Concentration Based on Micelle to Solvent Stacking

Ionic liquids in enhancing the sensitivity of capillary electrophoresis: Off‐line and on‐line sample preconcentration techniques

Contact Info

Product

Resources

About