Polyelectrolytes Assembly: A Powerful Tool for Electrochemical Sensing Application

Abstract

The development of sensing coatings, as important sensor elements that integrate functionality, simplicity, chemical stability, and physical stability, has been shown to play a major role in electrochemical sensing system development trends. Simple and versatile assembling procedures and scalability make polyelectrolytes highly convenient for use in electrochemical sensing applications. Polyelectrolytes are mainly used in electrochemical sensor architectures for entrapping (incorporation, immobilization, etc.) various materials into sensing layers. These materials can often increase sensitivity, selectivity, and electronic communications with the electrode substrate, and they can mediate electron transfer between an analyte and transducer. Analytical performance can be significantly improved by the synergistic effect of materials (sensing material, transducer, and mediator) present in these composites. As most reported methods for the preparation of polyelectrolyte-based sensing layers are layer-by-layer and casting/coating methods, this review focuses on the use of the latter methods in the development of electrochemical sensors within the last decade. In contrast to many reviews related to electrochemical sensors that feature polyelectrolytes, this review is focused on architectures of sensing layers and the role of polyelectrolytes in the development of sensing systems. Additionally, the role of polyelectrolytes in the preparation and modification of various nanoparticles, nanoprobes, reporter probes, nanobeads, etc. that are used in electrochemical sensing systems is also reviewed.

Superabsorbent Hydrogels in the Agriculture and Reclamation of Degraded Areas

“…In the case of polymerisation of an acrylic acid solution, the highest absorbency is obtained after neutralizing the acid in the range of 60 to 85% mol, using a solution of sodium (potassium or ammonium) hydroxide and/or carbonate [35,70,77,78]. Polymers obtained as a result of the polymerisation of acidic or alkaline monomers, i.e., those containing groups capable of dissociation, are classified as polyelectrolytes [74]. In the case of polymerisation of non-ionic monomers such as acrylamide or acrylonitrile, the obtained polymers can be transformed into polyelectrolytes as a result of hydrolysis of the amide [75,76] or nitrile group [73].…”

Advances in Bioelectrode Design for Developing Electrochemical Biosensors

“…105−107 The role of polyelectrolytes in the development of the sensing systems and the architectures of the sensing layers have been reviewed. 108 Organic frameworks, such as metal−organic frameworks (MOFs) and covalent organic frameworks (COFs), have also been explored for biosensor applications. MOFs have emerged as an immobilization matrix for protecting enzymes.…”

“…The main purposes of using these materials are to improve the electron/charge transfer efficiency, increase the active surface area of the electrode, and serve as an immobilization matrix to provide better stability and reusability of the biorecognition element. Various bio/polymers such as, polysaccharides, proteins, and their composites are widely used as the immobilization matrix. − Synthetic polymers such as redox polymers and conducting polymers have also been explored for this purpose. , Many redox polymers, used as electron transfer mediators and enzyme immobilizing matrices, offered improved bioelectrode performance. , Conducting polymers have often been used for improving signal transduction and amplifications and to serve as an immobilization matrix. ,, Polyelectrolytes, which have ionic properties, help to incorporate various species with sensing/mediating/transducing properties and serve as a matrix for immobilizing the biorecognition elements. − The role of polyelectrolytes in the development of the sensing systems and the architectures of the sensing layers have been reviewed . Organic frameworks, such as metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), have also been explored for biosensor applications.…”

Artificial photosynthesis systems for solar energy conversion and storage: platforms and their realities

“…The self-assembly of polyelectrolyte polymers in this APS provided a useful strategy for the controllable integration of the photocatalysis and biocatalysis system. However, electrons are inevitably lost in the polyelectrolyte platform during migration, 126 which is a challenge to address in the future development of the technology.…”