Supramolecular Materials for Optical and Electrochemical Biosensors

Abstract

It is incontestable that the interactions and bonds that keep molecules united to generate unique supramolecular compounds, with individual properties, morphologies and behaviour, are of special dynamics and singular forces. Therefore, it is necessary to discuss and consider the types of interactions that may occur in a determined system, their dynamics and number, which directly act on the energetic balance that strengthen the union between participants and give rise to a supramolecule.In this chapter, a number of such supramolecular systems that find application as any component of a biosensor are presented and discussed, considering intermolecular interaction forces that confer them shape, function and unique properties. To better understand their structural dynamics and the mechanisms through which they can be used in biosensing, a brief explanation on the interaction thermodynamics, types of intermolecular interactions that compete against each other and the energetic equilibrium that originate and stabilize supramolecular systems is given. To explain how this balance of forces can be extensively exploited to develop methods to produce supramolecular compounds, an overview on supramolecular strategies is presented and their contribution is explored in each example presented in this text, to evidence the importance of planning and developing methodologies of preparation, based on

Electrochemical Biosensors Containing Pure Enzymes or Crude Extracts as Enzyme Sources for Pesticides and Phenolic Compounds with Pharmacological Property Detection and Quantification

“…Several examples of biosensors prepared with crude extracts as enzyme sources were reported [28][29][30]. Many studies aim to obtain less expensive biosensors with higher durability, since crude extracts mimic the natural enzyme environment.…”

“…In addition, cofactors and coenzymes can be present in the crude extract. Martins et al [28] reported the preparation of a biosensor using the crude extract of the pumpkin Cucubita pepo for paracetamol detection in aqueous solution, and Benjamin et al [29] reported a biosensor prepared with a crude extract, which was a source of the polyphenol oxidase, anchored with cerium nanoparticles for rutin detection in solution, showing a limit of detection of the 0.16 μmol L −1 .…”

Evolution of Supramolecular Systems Towards Next-Generation Biosensors

“…The low energy barrier for disassembly and reassembly of supramolecular structure ( Li J. et al, 2020 ), specifically those that are based on aggregates held by π-π interactions, also support good signal amplification. Curently available supramolecular materials have been made from inorganic systems, organic structures, polymers, hybrid materials, charged molecules, crystals, gels, metallic nanoparticles, and others by combining various types of non-covalent interactions ( Martins et al, 2015 ; Wang et al, 2016 ). Many of these materials and their composites can be functionalized in a facile manner to achieve water solubility, making such supramolecular building blocks more relevant for sensing biological analytes under aqueous environments ( Wang et al, 2016 ).…”