Vol.:(0123456789) 1 3 Chemistry Africa (2020) 3:513–533 https://doi.org/10.1007/s42250-020-00177-w REVIEW Applications of Chitosan in Molecularly and Ion Imprinted Polymers Abdelhafd Karrat 1  · Abderrahman Lamaoui 1,2  · Aziz Amine 1  · José María Palacios‑Santander 2  · Laura Cubillana‑Aguilera 2 Received: 30 May 2020 / Accepted: 11 August 2020 / Published online: 26 August 2020 © The Tunisian Chemical Society and Springer Nature Switzerland AG 2020 Abstract Chitosan is a natural polysaccharide derivative of chitin component that has been used in a wide range of felds because of their outstanding advantages, including non-toxicity, biodegradability, biocompatibility, anti-allergic, anticoagulant, anti- fungal and antimicrobial. Due to its excellent properties, it attracted signifcant attention in numerous applications such as medicine, food, and analysis felds. Recently, this polymer has been broadly utilized for the preparation of molecularly imprinted polymers (MIPs) and MIP composites. MIP is a synthetic receptor obtained by the polymerization of functional monomers in the presence of a template. The extraction of the template leaves behind specifc cavities. In fact, according to our bibliographic studies about this topic, we found that chitosan is generally used in two diferent ways: (1) as imprinting polymer with a selected crosslinking agent to create specifc cavities for the template, and (2) as additive material for MIP composite preparation. That is exactly the main goal of this review, which will be focused on discussing the roles of chitosan for MIP and MIP composite elaborations, after presenting some generalities about chitosan and MIP. A brief overview of the recent applications of MIPs and MIP composite based on chitosan is presented, but the focus is primarily put on separation and sensing applications. Among that, those designed to separate/detect heavy metals, drugs, biomolecules, and pesticides are highlighted. Keywords Molecularly imprinted polymer · Chitosan · Composite · Sensors · Separation 1 Introduction Chitosan is a biopolymer derivative of chitin components extracted from the shells of crustaceans. The deacetylation reaction of chitin by chemical method (with a concentrated basic solution) or by an enzymatic method (with chitin- deacetylase) leads to chitosan. The latter product presents a linear chain polysaccharide composed of two monomeric units distributed randomly: deacetylated D-glucosamine and N-acetyl-D-glucosamine [1]. Chitosan has a similar structure as cellulose, except in the functional group on C2 position of the D-glucosamine unit, such that cellulose has a hydroxyl group (–OH), whereas chitosan possesses an amino group (–NH 2 ) [2]. Chitosan exhibits important biological properties: it is non-toxic, biodegradable, biocompatible, anti-allergic, anti- coagulant, antifungal, and antimicrobial. All of them allow chitosan to be used in a multitude of applications, including medicine, food, and sensing [3]. Furthermore, chitosan has become an important polymer included in the preparation of molecularly imprinted polymers (MIPs) and ion-imprinted polymers (IIPs) and their composites. The presence of hydroxyl and amine groups in chitosan facilitates its modi- fcation. It can react with diferent cross-linking agents, such as aldehyde (glutaraldehyde), epoxide (epichlorohydrin), and acids (sulfuric acid) [4–6], among others. Chitosan has been used also as an additive material for the preparation of MIP composites [7]. MIPs are synthetic materials containing specifc cavities to a target molecule. The operation mechanism of MIP to * Aziz Amine azizamine@yahoo.fr * José María Palacios-Santander josem.palacios@uca.es 1 Faculty of Sciences and Techniques, Hassan II University of Casablanca, B.P. 146, Mohammedia, Morocco 2 Department of Analytical Chemistry, Institute of Research on Electron Microscopy and Materials (IMEYMAT), Faculty of Sciences, Campus de Excelencia Internacional del Mar (CEIMAR), University of Cadiz, Campus Universitario de Puerto Real, Polígono del Río San Pedro S/N, Puerto Real, 11510 Cádiz, Spain