Frontal Analysis Capillary Electrophoresis: Recent Advances and Future Perspectives

Abstract

The developments on frontal analysis capillary electrophoresis (FACE) from 2012 to 2017 to study interactions of simple and complex systems are reviewed. Most research papers focused on therapeutic drug-related studies; however, other studies include chemical sensing, drug delivery, inhibitor screening and capillary coating. New ligand-substrate systems such as template-molecularly imprinted polymer systems were reported. Comparison of FACE with other analytical techniques used to investigate binding interaction, and the determination of binding parameters using different isotherm models are also covered. In 2017, eight research papers were reported including new detection by ESI-MS. Future research direction of FACE may include high sensitivity detection and throughput screening of drugs, natural products and biomarkers for clinical diagnosis.

Recent developments in capillary and microchip electroseparations of peptides (2019–mid 2021)

“…ACE includes several modes based either on (i) the separation of the interacting species and the determination of their equilibrium concentration, such as in the Hummel-Dreyer method [121,124], the vacancy peak method [121,125], frontal analysis [126][127][128], continuous frontal analysis [121,129], and kinetic CE [130], or (ii) the detection of a specific physicochemical property of the complexed analyte or its binding partner, mostly the changes of analyte effective mobility in the mobility shift ACE [131] or changes of migration times of analyte in the partial-filling ACE (PF-ACE) [132,133]. All these methods utilize the differences in the migration velocities of the interacting species; their critical comparison can be found in the recent review [121].…”

Contactless conductivity detector as a tool for improving universality and sensitivity of capillary electrophoresis‐frontal analysis: Proof of concept

“…CE, or more precisely affinity capillary electrophoresis (ACE), has other important benefits besides those mentioned above generally for CE, such as no need for (i) highly purified samples, (ii) immobilization, and (iii) labeling of interacting partners [7]. ACE can be performed in several basic modes, and more detailed information on individual modes can be found in various reviews [3,4,8,9]. In recent years, mobility shift-affinity capillary electrophoresis (ms-ACE) and capillary electrophoresis-frontal analysis (CE-FA) are the most used modes [4,8,10].…”

Sensitivity enhancement of capillary electrophoresis‐frontal analysis‐based method for characterization of drug‐protein interactions using on‐line sample preconcentration

“…CE-frontal analysis (CE-FA), which belongs to the group of affinity CE (ACE) modes [1], is a well-established technique for the study of different interactions. Together with mobility-shift ACE, it is one of the most used ACE modes for the characterization of plasma protein-drug bindings [2,3]. CE-FA provides the option of studying interactions without the immobilization or labeling of one of the partners.…”

“…Recently the review tracking the use of affinity ACE, especially ms-ACE and CE-FA, and microscale thermophoresis techniques for the evaluation of binding among different molecules during the 5 years 2016-2021 has been published [6]. A last comprehensive summary of the development of the CE-FA method and its applications was published by Romano and Quirino in 2018 [3]. Since then, CE-FA has been extended and improved by a displacement study [7], automated online sample mixing directly in the capillary [4], external pressure-assisted CE-FA [8,9], and a combination with MS detection [10].…”